Traders are aggressively borrowing recently issued Treasuries to establish short positions, driving up borrowing costs for key short-dated securities—a dynamic that could lend crucial support to next week's government debt auctions.

With Treasury yields rebounding to multi-year highs, the cost of borrowing the current 2-year and 5-year notes over the weekend has become notably more expensive. On Friday, the 2-year yield rose 7 basis points to 4.74%, marking its highest level since mid-2024.

The rising borrowing costs signal that, in the repo market, traders are willing to pay a premium to secure these specific notes over other collateral. This indicates these bonds are trading in a "special" state, a key sign of heightened demand.

John Canavan, an analyst at Oxford Economics, noted in a research report that the 2-year and 5-year notes are poised to enter an unexpectedly special repo status heading into the weekend, with traders positioning ahead of next week's auctions for 2-year, 5-year, and 7-year securities.


Rising Yields Fuel Short Positioning

The persistent climb in yields is a primary driver behind this surge in repo costs. As yields across the curve push higher, traders are incentivized to borrow specific Treasuries in the repo market to build short positions, willingly absorbing steeper borrowing expenses.

According to broker ICAP, the overnight repo rate for borrowing the current 2-year note on Friday hovered around 0.79%, easing from approximately 0.95% earlier that morning around 7:30 AM New York time. Meanwhile, the repo rate for the current 5-year note plunged to negative 0.85%, down from a previous reading of 0.29%.

In contrast, the general repo rate for Treasury collateral stood near 3.88%. A lower repo rate reflects stronger demand to borrow that specific security. Data from CME Group indicates that during the post-FOMC selloff, significant new risk exposure was added to front-end and belly futures contracts, consistent with the build-up of fresh short positions.


"When-Issued" Mechanics Deepen Supply Squeeze

Beyond short positioning, the "when-issued" trading mechanism ahead of auctions is another key factor boosting repo costs. Treasuries that have been announced but not yet issued often trade in the market before the auction date.

Wall Street dealers use when-issued securities for hedging and quoting, but since the physical notes do not yet exist, the actual supply is extremely limited. This scarcity forces dealers to pay higher borrowing costs in the repo market to source the paper.

This supply tightness is typically viewed as a favorable omen for upcoming auctions: falling repo rates may also indicate that holders are reducing the amount of securities available for lending, further tightening market liquidity.


Rising Repo Fails, Fed Holdings Offer a Buffer

The market strain is also visible at the settlement level. Data from the Depository Trust & Clearing Corporation (DTCC) shows that the daily total of Treasury repo fails climbed to $67.6 billion on September 17, up from $36.7 billion the previous trading day and surpassing the five-day moving average of $54.7 billion.

However, the Federal Reserve's holdings are providing some cushion to the market. Since ending quantitative tightening in 2025 and continuing to roll over maturing securities at auctions, the Fed holds approximately 11.4% of the most recent 2-year and 5-year issues, representing around $8.9 billion and $9.0 billion, respectively.

In Thursday's Fed daily securities lending operation, dealer bids for both the 2-year and 5-year notes were fully satisfied, indicating that current supply can still meet market demand.