31 CFR § 356.21 - How are awards at the high yield, discount rate, or discount margin calculated?
(a) Awards to submitters. We generally prorate bids at the highest accepted yield, discount rate, or discount margin under § 356.20(a)(2) of this part. For example, if 80.15% is the announced percentage at the highest yield, discount rate, or discount margin, we award 80.15% of the amount of each bid at that yield, discount rate, or discount margin. A bid for $100 million at the highest accepted yield, discount rate, or discount margin would be awarded $80,150,000 in this example. We always make awards for at least the minimum to bid, and above that amount we make awards in the appropriate multiple to bid. For example, Treasury bills may be issued with a minimum to bid of $100 and multiples to bid of $100. Say we accept an $18,000 bid at the high discount rate, and the percent awarded at the high discount rate is 88.27%. We would award $15,900 to that bidder, which is an upward adjustment from $15,888.60 ($18,000 × .8827) to the nearest multiple of $100. If we were to award 4.65% of bids at the highest accepted rate, for example, the award for a $100 bid at that rate would be $100, rather than $4.65, in order to meet the minimum to bid for a bill issue.
(b) Awards to customers. The same prorating rules apply to customers as apply to submitters. Depository institutions and dealers, whether submitters or intermediaries, are responsible for prorating awards for their customers at the same percentage that we announce. For example, if 80.15% is the announced percentage at the highest yield, discount rate, or discount margin, then each customer bid at that yield, discount rate, or discount margin must be awarded 80.15%.