The monthly market va'l ue statist'ics on outstanding United States Treasury debt are reported for the 198i-1984 period. In addition, a monthly series on privately held gross federal debt is reported for the extended 7942-1984 period, together with monthly security-price indices for various federal debt aggregates. Examination of the stochastlc structure of T-Bi1i prices indicates that the riskiness of T-Bills has increased dramatically in recent yea rs .