To know which bar format the contract should name, read the operational shape of the holding it produces. A 400 oz Good Delivery bar settles into loco-London clearing and lends into wholesale structures. Bilateral settlement of 1 kg kilobars runs across loco-Zurich, loco-Singapore, loco-Hong Kong, and loco-Dubai, in any quantity from one bar upward. The 100 oz bar fits inside COMEX-aligned flow and carries a wider bid outside it. Metal and fineness floor are common across the three, priced off the same LBMA reference. What changes is the route each format takes through the wholesale market once owned.
Format selection commits the buyer to an operational shape that travels with the holding. Vault acceptance at sight or only with re-assay. Premium paid at acquisition and recovered at exit. The unit of partial liquidation. The chain of integrity that admits the bar into wholesale lending and clearing — and breaks the moment the bar leaves accredited custody.
Three formats and four dimensions structure the decision. The formats are the LBMA Good Delivery bar, the 1 kg kilobar, and the 100 oz bar. The dimensions are premium structure and pricing, vault acceptance and lendability, exit liquidity and buyback, and allocation granularity. Each format reads cleanly against the others only across all four together.
The LBMA Good Delivery gold bar
Three properties together make a 400 oz bar a Good Delivery bar: physical specification within the LBMA tolerance band, production by a refiner on the current Good Delivery List, and continuous custody since cast inside the chain of accredited vaults and carriers. The LBMA Good Delivery bar holds its wholesale-market status only while all three are in place; the absence of any one removes the bar from at-sight acceptance even when the metal itself is unchanged.
Specification
Four parameters are checked at every handover into an approved vault: weight, fineness, geometry, and surface marks. For the format-choice question, three of them bind: gross weight in the 350 to 430 fine troy ounce range — the ≈400 oz / 12.5 kg block the wholesale market settles around — minimum fineness of 995.0 parts per thousand fine gold, and verification through refiner mark, serial number, fineness stamp, and year of manufacture stamped on the bar at cast.
Verification works through the marks. The serial number ties a specific bar to the production lot it came from and to the refiner’s records of that lot. Refiner mark and year of manufacture together let a counterparty look up the producer on the Good Delivery List version in force when the bar was cast and read the bar against the specification rules of that year.
The Good Delivery List and refiner accreditation
Accreditation shifts the trust point from individual bars to refiners. The LBMA Good Delivery List names the refiners whose output the wholesale market accepts at sight — at vault receipt, at settlement, and as collateral — and is maintained against published technical, financial, and supply-chain criteria. Argor-Heraeus SA (Switzerland) and Heraeus Precious Metals appear on the current Good Delivery List for gold as part of the Heraeus group of refining operations. Bars cast to Good Delivery specification by a listed refiner are acceptable at sight into approved London vaults and into the parallel approved vault networks of the major loco markets — Zurich, New York, Singapore, Hong Kong — without further verification at the bar level.
Chain of integrity
Good Delivery status persists only while the bar stays inside the chain of integrity — the unbroken sequence of LBMA-approved refiners, vaults, and carriers with continuous accountability for the bar from cast forward. While the bar moves between approved vaults under accredited carriers, with each handover documented, it is taken at sight by the next vault. The chain of custody removes the need for re-assay at every step.
When a bar leaves the chain — through private custody, an unaccredited carrier, or a documentation gap — physical specification is preserved while at-sight acceptance is forfeited. The structural point binds at acquisition: where the holding’s value depends on acceptability into wholesale lending, central-bank-facing transactions, or clearing settlement, accredited custody belongs to the asset itself. Move the bar to a private safe outside the chain, and the metal stays the same. The asset does not. Settlement against it then requires a step that did not previously exist, and the bid the bar will see on exit reflects that step.
The kilobar
Below the 12.5 kg Good Delivery block, the wholesale market trades the 1 kg bar. The same refining lines run both formats — a kilobar from Argor-Heraeus SA or Heraeus Precious Metals carries the same supply-chain provenance as a 400 oz bar from the same operation — yet weight class, production method, settlement layer, and market role each change with the format.
Specification
A 1 kg gold bar carries 32.1507 troy ounces of fine gold at conventional 999.9 fineness — four nines, against the 995.0 floor that defines Good Delivery acceptability. The higher fineness is the kilobar’s commercial standard, and bars below four nines find very limited buyers in the segment that takes this format. Dimensions vary by refiner and production method; the kilobar has no single dimensional rulebook of the kind Good Delivery imposes. A typical cast kilobar from Argor-Heraeus runs in the order of 117 × 53 × 9 mm; a typical minted kilobar runs flatter and longer.
The marks travel with the kilobar in the same form they take on a Good Delivery bar — refiner mark, serial number, fineness stamp, weight — and serve the same verification function. A counterparty receiving the bar identifies the producer through the mark, confirms refiner status at the time of cast against the current Good Delivery List, and ties the specific bar to the producer’s records of the production lot. Kilobar production from an LBMA-accredited refiner inherits the supply-chain assurance of that refiner’s listing — Responsible Gold Guidance compliance, Proactive Monitoring, the auditable origin chain — without conferring Good Delivery acceptance on the bar itself.
Cast and minted production
Casting pours metal directly from the refining line into an open mold. The bar cools with the surface texture and slight shape variation that pouring produces, and the marks are stamped after the pour. Cast production runs fast and at low cost per bar, and the cast format is what wholesale buyers most often see at the refinery-origin end of the market. Argor-Heraeus and Heraeus Precious Metals both produce cast kilobars at scale, and most allocated-storage holdings of kilobars consist of cast bars.
The minted format starts at the press. A refined blank is rolled to thickness, blanked to size, and struck under a press that applies the design and the marks in a single operation. The output has sharp edges and an even surface — a more decorative object — at meaningfully higher production cost per bar than the cast format. Minted kilobars therefore carry a higher premium than cast kilobars from the same refiner. The premium covers production economics — design, blank preparation, press operation — at higher cost per bar than the cast pour. The differential typically does not return on exit; most wholesale buyback bids do not distinguish cast from minted at the kilobar level.
Across preservation, balance-sheet allocation, and other holdings intended to sit in vault storage and eventually be sold or redelivered against, the cast kilobar is the format the market is built around. Minted production serves use cases where the physical object matters in itself — gift, presentation, or specific retail-adjacent flows out of scope for wholesale acquisition.
Where the kilobar sits in the market
Kilobars produced by LBMA-accredited refiners are acceptable into LBMA-approved vaults and move under the same accredited carrier network as Good Delivery bars. Loco-London Good Delivery clearing — the layer in which ownership of metal sitting in a London Good Delivery vault transfers between parties while the metal stays in vault — runs only on 400 oz bars. A kilobar holding can be vaulted in the same vault complex and held under the same allocated-custody arrangement; the clearing layer above it works on a different unit.
The clearing-layer absence is a structural property of the kilobar segment. The kilobar exists to give the wholesale market a unit size matching the value blocks buyers actually transact in. At recent gold prices, a 12.5 kg Good Delivery bar represents roughly a million-dollar-scale block; a kilobar represents roughly an 80,000-dollar-scale block. Holdings sized to mid-six- and low-seven-figure value, intended to be divisible across custody locations, across staged exits, or across discrete blocks for selective sale or movement, are what the kilobar is built around — granularity at refinery-origin quality.
Loco-Zurich, loco-Singapore, loco-Hong Kong, and loco-Dubai all operate active kilobar flows below the 400 oz block size. Each runs a separate vault network with its own carrier conventions and its own bid behavior on exit. A kilobar in an LBMA-approved vault in Zurich is the same physical object as a kilobar in Singapore; the bid the buyer will see on exit, and the path back to loco-London settlement if that path becomes useful, vary by location. A holding placed in Zurich and a holding placed in Singapore are, in operational terms, two different positions in the same metal.
The 100 oz gold bar
COMEX gold futures contract specifications drive the 100 oz format. Each contract settles physical against bars of 100 troy ounces (±5% tolerance) at minimum 995.0 fineness, deliverable into COMEX-approved depositories in and around New York. The bar is built to that contract specification, and most trading and storage flow around the format sits inside the same COMEX-aligned ecosystem — approved depositories, exchange-recognized brands, warrants representing depository receipts on specific bars.
A 100 oz bar from an LBMA-accredited refiner is acceptable into LBMA-approved vaults outside the COMEX ecosystem. Commercial gravity, though, sits on the western side of the Atlantic. Wholesale buyers in loco-London, loco-Zurich, and the Asian loco markets transact almost exclusively in 400 oz Good Delivery bars and 1 kg kilobars. A 100 oz bar from an accredited refiner is acceptable in those markets, with bid spread on exit reflecting placement cost into a non-native segment — the receiving counterparty has to find the bar a flow that wants it.
Two situations make the 100 oz format the right fit for a wholesale buyer outside the COMEX delivery flow. The holding is structured against COMEX exposure — a corporate hedge, a futures-delivery commitment, or a position that needs to be deliverable into a COMEX warrant — and the bar is sized to that purpose. Or the acquisition draws from a counterparty whose existing inventory is in 100 oz form, and re-barring at a refinery would add cost and reset the manufacture date on the asset.
Outside those two situations, the 100 oz format has narrow utility for buyers acquiring physical gold for preservation, balance-sheet allocation, or wholesale lending. The 400 oz Good Delivery bar serves the upper end of those use cases; the kilobar serves the divisible-block end of the same wholesale market. Bid friction on the 100 oz bar outside COMEX flow follows from that wholesale-market structure: the dominant units in loco-London, loco-Zurich, and the Asian loco markets are 400 oz and 1 kg, and a 100 oz bar entering those markets carries the placement cost of a non-native unit.
Where format choice plays out
Three formats — Good Delivery, kilobar, 100 oz — meet the buyer along four operational dimensions, with measurable differences along each. Premium paid at acquisition and premium recovered at exit. Which vaults take the bar at sight, and what the bar can be lent into without leaving its accreditation behind. The bid spread on exit and the size of the smallest exit possible without re-barring. And the granularity at which a holding can be moved, split, or partially reallocated.
The four dimensions act independently. The 400 oz Good Delivery bar leads on premium tightness and bid depth; the kilobar leads on granularity; the 100 oz bar leads inside the COMEX flow it was built for. Each dimension distributes leadership differently across the three formats, and format choice resolves as a position on all four at once.
Premium structure and pricing
The reference price is the same across the three formats — the LBMA AM and PM gold price, fixed twice each London business day, used as the wholesale benchmark for physical settlement. The premium between reference and invoice is where the formats diverge.
Acquired at refinery origin, the 400 oz Good Delivery bar carries the narrowest per-ounce premium in the wholesale market for physical gold. Several mechanics combine to compress it: the bar is the unit the wholesale market is built around, the 995.0 floor is the reference fineness for that market, the production unit is a single pour, and the settlement and custody layer admits the bar at sight at every handover. The premium covers refiner margin, accreditation cost spread across production, and counterparty working capital, and scales by the ounce — so per-ounce cost on a 400 oz bar is the lowest a buyer will see on accredited-refiner gold.
Kilobar premium runs higher per ounce and varies by production method and refiner identity. Cast kilobars carry a smaller premium than minted kilobars from the same refiner because production cost per bar is lower. Refiner identity feeds in directly — a kilobar from Argor-Heraeus or Heraeus Precious Metals carries a different premium from a kilobar by an equally accredited but less wholesale-active producer, because the resale market reads the marks. On a 1 kg cast bar from a major Swiss refiner, the premium can run as a multiple of the per-ounce premium on a 400 oz Good Delivery bar from the same operation. The buyer pays for the smaller production unit, the higher 999.9 fineness, and the role kilobars play as discrete tradable blocks below wholesale slab size.
Inside COMEX-aligned flow, the 100 oz bar prices close to the Good Delivery premium because the format is native there. Sold outside that flow, the per-ounce premium widens; the bid reflects what the receiving counterparty would have to do to place the bar back into a market that takes it as the dominant unit.
Premium asymmetry binds at exit. The premium paid at purchase is partially recovered in the bid the holding will eventually receive, but recovery is asymmetric: kilobar buyback bids in many wholesale flows compress toward Good Delivery pricing, so a buyer who paid a kilobar premium at acquisition recovers only part of the differential over the 400 oz premium at sale. Over a long holding period the gap is small relative to the gold price itself; it is one component of the long-run cost of granularity.
Vault acceptance and lendability
The 400 oz Good Delivery bar is acceptable at sight into the LBMA-approved vault networks in London, Zurich, New York, Singapore, and Hong Kong, and into the equivalent networks operated by the other principal loco markets. At sight means the bar is verified by serial number, refiner mark, and chain-of-custody documentation, and admitted to custody without further assay. Loco-London settlement — the wholesale clearing layer in which ownership of metal in London Good Delivery vaults transfers between parties while the metal stays in vault — runs on these bars, and loco-Zurich and the smaller parallel loco markets clear the same way. A Good Delivery bar held in any of these systems transfers between parties through a book entry, with the bar staying in the same vault.
Kilobar acceptance into LBMA-approved vaults works under the same allocated-custody discipline: the bar is held in the buyer’s name, identified by serial number, reconcilable on audit. Loco-London Good Delivery clearing, however, does not extend to the kilobar holding. Kilobar settlement runs bilaterally — title transfer between counterparties — and where the parties want loco-market acceptance, the kilobar moves through loco-Zurich, loco-Singapore, loco-Hong Kong, or loco-Dubai, where kilobar-scale settlement is the norm. A kilobar in an LBMA vault in London is housed in the same vault complex as the Good Delivery flow, with settlement happening on a different layer.
A 100 oz bar from an accredited refiner moves into LBMA-approved vaults under the same logic, and into COMEX-approved depositories where it sits as the native format. Holdings in a COMEX depository can be issued as warrants — depository receipts representing specific bars — through which the format participates in COMEX delivery flows.
Lendability follows acceptance. Gold lending — placement of physical gold with a counterparty that pays a lease rate for the use of the metal — runs primarily on Good Delivery bars in loco-London. Sovereign reserve managers placing gold for return on idle reserves transact in Good Delivery, and so does the use of gold as collateral in clearing structures and in bilateral wholesale arrangements that depend on at-sight acceptance. Kilobar holdings can be lent — wholesale kilobar lending markets operate in Zurich and in Asian loco markets — under different structures, with a different counterparty pool, at different lease rates. Lendability of physical gold tracks the format’s loco-market layer.
Where the holding’s use is straight preservation in vaulted custody — no lending, no collateralization — format lendability carries no operational weight on the holding. Where the holding is expected to feed any of those layers, lendability is a property of the format and the loco-market layer it sits in: 400 oz Good Delivery in loco-London opens loco-London lending; kilobars in Zurich open Zurich kilobar lending; 100 oz bars in a COMEX depository open COMEX-aligned uses. A holding stays inside the lending pool that its format and location admit it to.
Exit liquidity and buyback
Exit liquidity is the bid the buyer will see on sale, the depth of the market that is willing to take the bar at that bid, and the smallest unit at which an exit can be made without re-barring.
The Good Delivery bar carries the deepest wholesale bid. Its market is the wholesale gold market itself — bullion banks, refiners, sovereign reserve managers, and the loco-London clearing flow that settles around the format. Sale to an accredited counterparty produces a bid close to spot, with a spread reflecting the counterparty’s onward placement cost. Fractional exit requires moving outside the format. The smallest sellable unit is one bar — roughly 12.5 kg, roughly a million-dollar-scale block at recent gold prices. Liquidating part of a four-bar holding means selling one bar; selling half a bar means re-barring into a smaller format, with melting and re-casting at an accredited refiner and the consequences of leaving and re-entering the chain of integrity.
The kilobar bid runs wider than the Good Delivery bid in absolute spread, consistent with the wider acquisition premium — the dealer paying the bid has the same kind of placement cost to recover on the way out. The trade-off is exit at the kilobar’s unit size, sold one bar at a time, in any quantity from one upward. With fifty kilobars in vault, liquidating a fifth means selling ten bars and leaving forty. The same liquidity question on a forty-bar Good Delivery holding becomes a re-barring exercise unless a whole bar is the right exit size.
Inside COMEX-aligned flow, the 100 oz bar exits cleanly. Holdings in a COMEX-approved depository can be sold against COMEX bid, delivered against a futures position, or placed through dealers active in the format. Outside that flow, the same bid friction returns: the receiving market reads the bar as non-native, and the bid reflects placement cost back into a flow that takes it.
Format efficiency at exit is measured against the exit shape the holding will generate. A holding planned for whole-position sale to a single wholesale counterparty exits most efficiently as Good Delivery; a holding planned for tranche drawdown across jurisdictions or time horizons exits most efficiently as kilobars. Exit unit size determines whether a partial liquidation runs by selling bars or requires re-barring at an accredited refiner — and re-barring puts the holding through the chain-of-integrity reset that comes with leaving and re-entering accredited custody.
Allocation granularity and partial reallocation
A physical gold holding is also a position the buyer may need to restructure during the holding period — moved between vaults, split across jurisdictions, reallocated in part to a new entity, partially delivered out, partially sold. Format determines the granularity at which any of this is possible.
Take a holding the size of four 400 oz Good Delivery bars — roughly a four-million-dollar-scale block at recent gold prices. In Good Delivery, the holding moves in four lumps. Moving half to a different vault means moving two bars; reallocating a quarter to a separate entity means transferring one bar’s title; selling a quarter at the day’s mid means selling one bar. The granularity of every operation on the holding is the bar.
The same metal held as kilobars is roughly fifty bars. The holding slices arbitrarily down to the kilobar’s unit size. Half to Zurich and half to Singapore distributes twenty-five bars to each vault. A reallocation of one-tenth to a new entity moves five bars. A staged exit over a year runs at roughly four bars a month, with the remainder still earning whatever exposure the holding was placed for. The buyer pays for this granularity twice — once in the kilobar premium at acquisition, again in the wider bid spread at exit — and during the holding, the format is what makes the operations possible without re-barring. As 100 oz bars the same metal is sixteen bars: coarser than kilobars, finer than 400 oz, mostly useful inside the COMEX-aligned flows where the format is native.
Cross-jurisdictional reallocation is where the granularity differential matters most. A buyer who acquires gold under one custody arrangement and later moves part of it into a vault under a different operator in a different loco market moves bars. Each bar that crosses a border crosses under accredited carriage, with documented chain of custody, with vault release on one end and vault acceptance on the other. International delivery of allocated bars runs through Brink’s and the parallel accredited carrier networks; the operation is well-defined and routine, and it is per-bar. Moving four bars and moving fifty bars are the same kind of logistical operation; the four-bar move is the smallest possible reallocation, while the fifty-bar move admits tranches that match whatever business or exposure logic motivated it.
Where the holding is static — placed once, held in vault, eventually sold whole — the granularity differential carries no operational weight. Where the holding is expected to be active during the holding period through partial liquidations, vault-to-vault transfers, allocations across entities, or deliveries against specific obligations, the granularity differential is significant. Format choice at acquisition is, in effect, a pre-commitment to a level of operational flexibility for the entire holding period.
Where each format fits
Three formats, three different fits to three different shapes of holding. The fit follows from what the holding is expected to do during the holding period — sit in vault, lend out, exit whole, exit in tranches, settle into clearing, deliver against futures. Each format specifies which of those the holding can do without leaving the unit it was placed in.
When the holding is wholesale-scale and expected to draw value from layers only Good Delivery participates in — loco-London clearing, gold lending, collateral use in clearing structures, deliverability into sovereign and bullion-bank counterparty flows — the 400 oz Good Delivery bar is the format that fits. Premium is the narrowest the wholesale market offers, exit bid is the deepest, and the settlement layer accepts the bar at sight at every handover. Granularity is the cost. The bar is the unit, and every operation on the holding — partial sale, reallocation, vault transfer, delivery — happens in 400 oz blocks; the holding behaves in lumps of that size for as long as it exists.
When the holding needs to be divisible — across custody locations, across staged exits, across discrete blocks that move or sell without affecting the rest of the holding — the 1 kg kilobar is the format that fits. Acquisition premium runs wider per ounce, exit bid runs wider, and the kilobar trades outside the loco-London clearing layer. The return is fifty bars of granularity per twelve and a half kilograms of metal: active management of the holding through partial liquidations matched to capital needs, reallocations across entities or jurisdictions, vault distributions between loco-Zurich, loco-Singapore, and loco-Hong Kong — operations that happen at the kilobar’s unit size and would require re-barring at the Good Delivery bar’s unit size. The wider premium and wider bid are paid in exchange for that operational flexibility across the holding period.
Inside a COMEX-aligned flow — a corporate hedge, a futures-delivery commitment, a holding structured for delivery into a COMEX warrant — the 100 oz bar is the native unit and the format that fits. The same fit holds when an acquisition draws from a counterparty whose existing inventory is in 100 oz form and re-barring at a refinery would cost more than accepting the format. Outside these uses, the format has narrow utility for preservation, balance-sheet allocation, or wholesale lending. The 400 oz bar covers the upper-scale use cases; the kilobar covers the divisible-block end; the 100 oz bar’s structural role sits inside COMEX delivery flow.
The decision reads as follows by buyer profile.
| Buyer profile and use case | Typical format | What the choice secures | What is given up |
|---|---|---|---|
| Wholesale-scale holding, single-entity, intended for lending or clearing-structure use | 400 oz Good Delivery | Narrowest premium, deepest bid, loco-London clearing, lendability into wholesale structures | Granularity — every operation is a 400 oz block |
| Long-term preservation holding sized in mid-six- to eight-figure ranges, vaulted, expected to be drawn down in tranches | 1 kg kilobar (cast) | Per-bar granularity, divisibility across vaults and across time, staged exits at the bar’s unit size | Wider acquisition premium and wider buyback bid; no loco-London clearing on the holding |
| Reserve allocation against a balance-sheet line, expected to be partially reallocated across entities or jurisdictions | 1 kg kilobar (cast) | Per-bar reallocation without re-barring; flexibility in vault distribution | Same premium and bid trade-offs as above |
| Holding structured for COMEX delivery, hedging, or warrant issuance | 100 oz | Native fit with COMEX delivery flow and approved depository structure | Native flow is narrower; exit outside COMEX-aligned market sees a wider bid |
| Mixed holding — wholesale block plus active tranche | Both: 400 oz core plus 1 kg satellite | Wholesale-market access for the core, granularity for the active layer | Two custody lines instead of one; allocation discipline between them |
Mixed-format holdings appear in the last row of the table and warrant a separate note. The structure pairs a wholesale-scale core in 400 oz Good Delivery bars — placed for the bid, lendability, and clearing access — with a smaller kilobar satellite for tranched exits, vault distribution, or staged reallocation. Both layers sit under one custody arrangement, with allocated records identifying every bar to the buyer, while behaving differently in market terms. The shape is uncommon and serves a specific case: holdings where wholesale-market access and operational granularity are both required at the same time. Format choice in such cases resolves to two formats together.
The format on the contract sets the holding’s operational envelope for the duration: the bid available at exit, the vault networks that take the bar at sight, the wholesale-market layers the holding participates in, and the granularity at which any of it can be moved, split, or reallocated. That envelope sits in the allocated records from the day the bar enters vault — by serial number, by refiner, by manufacture date — and travels with the bar through every subsequent transaction the holding generates.