As of November 30, 2025, there has not yet been trillions of dollars of additional cumulative demand for U.S. Treasuries driven by dollar‑backed stablecoins under the GENIUS Act, but the prediction was explicitly framed as occurring “over the coming years” after enactment, so it is too early to judge it right or wrong.

Key facts:

• The GENIUS Act was passed by Congress and signed into law in mid‑2025 (Senate passage on June 17, 2025; reporting on it being signed into law on July 18, 2025). (reuters.com)
• Following enactment, one analysis estimates that between July and November 2025, stablecoin issuers bought about $44 billion in Treasury bills to comply with the new 100%‑backing requirements, raising the stablecoin market cap from about $260 billion to roughly $304 billion. (cryptowakeup.com) That’s tens of billions, not trillions, of incremental demand so far.
• Broadly, dollar‑backed stablecoins already hold on the order of $150–200+ billion in Treasuries as reserves, given total stablecoin market caps in the low‑hundreds of billions and reserve ratios heavily weighted to T‑bills. (coinlive.com) This is material but still far below “trillions.”
• However, official and industry projections after GENIUS was enacted envision exactly the kind of outcome Sacks referenced: for example, U.S. Treasury and TBAC analyses, as well as bank research (Standard Chartered, Citi, etc.), project stablecoin market caps could reach $1–3.7 trillion+ by 2028–2030, implying $1–2+ trillion of additional demand for short‑term U.S. government securities if current reserve structures persist. (mdpi.com) Senior officials like Treasury Secretary Scott Bessent have publicly cited similar multi‑trillion‑dollar potential demand. (mdpi.com)

Putting this together:

• The descriptive part of Sacks’s statement — that studies project the GENIUS Act–style stablecoin regime could generate trillions in new Treasury demand — is supported by multiple government and bank analyses.
• The forecasted outcome itself (actual trillions of extra demand materializing) is meant to unfold over several years (often modeled out to 2028–2030). Only a few months of post‑enactment data are available, and the realized additional demand so far is in the tens of billions, while the relevant horizon is multi‑year.

Because we are still near the beginning of that horizon and the projected magnitudes have not yet had time to either materialize or clearly fail, the correct assessment today is “inconclusive (too early)”, not definitively right or wrong.