The gold desk’s cash reserve has a yield. Which denominator is it using?

Start with the cash flow, not the biggest percentage

A gold allocation often sits beside a cash reserve. That reserve may fund a future bullion purchase, a trading account or an unrelated payment. Its advertised yield can look directly comparable with another account’s percentage even when the calculations use different bases. A comparison should begin with the amount paid, amount received, elapsed days and conditions for receiving the money. Only then should it move to annualized rates.

TreasuryDirect explains that a bill bought below face value pays face value at maturity. The difference is its interest. Its discount-price formula uses face value, the discount rate, the actual time to maturity and a 360-day denominator. A discount rate is therefore not automatically the percentage earned on the dollars actually invested. This article uses invented numbers to expose that distinction; it quotes no current bill auction or deposit offer.

Source notes: [1] TreasuryDirect · Understanding pricing and interest rates

One hypothetical bill, three useful numbers

Assume a hypothetical 90-day bill with a face value of US$10,000 and a bank discount rate of 4%. The price formula gives US$10,000 × [1 − (0.04 × 90 ÷ 360)] = US$9,900. Holding it to maturity produces a US$100 difference before costs and tax. Relative to the US$9,900 paid, the 90-day return is approximately 1.0101%. Relative to face value, the same US$100 is 1%.

Using a simple 365-day annualization of the purchase-price return produces approximately 4.0965%: US$100 ÷ US$9,900 × 365 ÷ 90. That arithmetic changes neither the payment at maturity nor the investment’s risk. It changes the reporting convention. Treasury describes its bill investment yield as based on purchase price and a 365- or 366-day year, in contrast to the bank discount convention. Longer bill maturities can require the relevant prescribed investment-yield formula rather than extending this short-bill illustration mechanically.

Source notes: [1] TreasuryDirect · Understanding pricing and interest rates · [2] U.S. Treasury · Daily Treasury bill rate definitions

Compounding adds an assumption

An effective annualization of that invented 90-day return would be approximately 4.16%, calculated as (10,000 ÷ 9,900) raised to the power 365 ÷ 90, minus one. That is a mathematical comparison rate. It does not establish that the same opportunity will be available repeatedly for a year. A future reinvestment can have a different price, term or rate, and cash may sit unused between transactions.

The CFPB’s U.S. deposit-account APY framework includes compounding and generally assumes principal and interest remain deposited for the relevant term without other transactions. Consequently, a bill’s quoted discount rate and a deposit APY cannot be ranked reliably merely by comparing the printed percentages. First model the same initial cash and the same required withdrawal date. Keep any annualized presentation secondary to the actual dollars expected under the stated assumptions.

Source notes: [3] Consumer Financial Protection Bureau · Regulation DD, Appendix A

Availability belongs in the comparison

A reserve needed for a near-term obligation should be examined for access as well as income. TreasuryDirect states that selling a marketable security held there requires transferring it to a bank, broker or dealer; it also specifies a 45-day initial holding restriction. A Treasury security held at a broker follows a different operational route. The label “marketable” does not mean every holding location supplies immediate cash on demand.

My practical comparison sheet would therefore contain a date for funds becoming usable, the route to obtain them early, any quoted exit price, transaction charges and the currency of the obligation. Ask a broker separately whether a security is accepted as collateral and on what terms. Ownership of an interest-bearing asset and cash available to meet a payment are different facts. This is a due-diligence framework, not a claim that any named account will accept a bill or release money within a particular deadline.

Source notes: [4] TreasuryDirect · Selling a marketable security

Use the result carefully in gold analysis

Once the conventions match, the reserve return can enter an opportunity-cost comparison. Use the same horizon and currency as the gold holding, account for its acquisition and custody costs, and distinguish a realized cash receipt from an annualized projection. A ten-year Treasury par yield from a market report is not the return promised on a three-month cash reserve. Substituting it can make an allocation argument appear more precise while changing the instrument being compared.

The separate weekly review examines nominal and real rate references as market context. This exercise addresses the cash mathematics of a specific holding period. It offers no preferred allocation between bullion and interest-bearing assets and no forecast of either. Its output is more modest and more useful: a comparison in which two rates cannot win an argument simply because one uses a more flattering denominator.