Resurgent mortgage convexity hedging threatens to amplify Treasury yield moves as the 'beast' returns to the government bond market.
The article explicitly discusses the return of mortgage hedging in the Treasury market. As MBS hedging flows return, US10Y yields are likely to experience amplified moves in both directions, with the net effect dependent on rate trends. The 'beast' signals higher volatility and a potential for sharper yield swings.
It amplifies the prevailing trend. In a falling rate environment, hedging adds buying pressure, pushing yields lower. In a rising rate environment, it adds selling pressure, pushing yields higher. The net directional impact depends on the broader rate outlook.
Historically, during episodes of intense hedging, it can account for significant intraday yield moves, sometimes exceeding 20 basis points in a single session. The impact is most pronounced when MBS durations are highly sensitive to rate changes, a condition that typically occurs when rates are near historical lows or breaking trend.
The mortgage hedging 'beast' is back in the Treasury market, reviving convexity-driven flows that amplify yield swings. The article details how MBS investors' hedging needs can whipsaw US government bonds, adding to rate volatility and complicating Fed policy transmission. The phenomenon retreated in recent years but reemerges as rate uncertainty persists.
It refers to the large-scale hedging activity by mortgage-backed securities investors who buy or sell US Treasuries to manage the duration risk of their MBS holdings. When rates fall, MBS duration extends, prompting investors to buy more Treasuries (driving yields lower); when rates rise, duration contracts, triggering Treasury sales (pushing yields higher). This creates a feedback loop that amplifies yield moves.
After a period of relative calm following the pandemic and aggressive Fed rate hikes, interest rate uncertainty has increased again, reviving the hedging needs of MBS portfolios. As rates become more volatile, the hedging activity intensifies, much as it did in prior episodes like the 2013 Taper Tantrum.
It magnifies directional moves: in a rally, hedging adds buying pressure that pushes yields even lower; in a selloff, it adds selling pressure that pushes yields higher. This can lead to overshoots and sudden reversals, increasing market volatility and complicating risk management for all bond investors.