Reasoning

1. Size of U.S. fiscal COVID relief
   Multiple nonpartisan and official oversight sources put total federal pandemic relief at a little over $5 trillion:

   • The Pandemic Response Accountability Committee (PRAC), created by the CARES Act, describes its mandate as overseeing the $2.2T CARES Act plus 5 other pandemic-related laws totaling over $5T in government funds. (en.wikipedia.org)
   • Analyses of where those funds went (direct payments, unemployment supplements, PPP, state/local aid, etc.) similarly summarize “over $5 trillion in direct relief spending”. (taf.org)
   • The Tax Policy Center’s briefing on the fiscal response estimates about $5.6T in federal tax cuts and spending hikes enacted as COVID relief. (taxpolicycenter.org)

2. Scale of Federal Reserve (monetary) support
   The Fed’s unconventional monetary actions mainly show up as balance-sheet expansion:

   • CRS reports the Fed’s balance sheet grew from $4.7T in March 2020 to almost $9T in May 2022, an increase of about $4.8T attributable to the COVID period. (congress.gov)
   • Financial press and Fed commentary consistently describe this as a peak around $9T, after which quantitative tightening began to shrink it back toward ~$6.6–7T. (wsj.com)

3. Combined scale vs. the prediction

   • Adding the fiscal support (~$5–5.6T) to the monetary expansion (~$4.8T) yields a combined figure on the order of $10T–10.5T in extraordinary U.S. COVID-era fiscal + monetary support, even before adjusting for overlaps (e.g., the Fed buying Treasuries issued to finance fiscal packages). (taxpolicycenter.org)
   • Independent trackers like the Committee for a Responsible Federal Budget’s COVID Money Tracker similarly find that, even counting “amount allowed” (authorizing ceilings for loans, guarantees, and facilities), U.S. support peaks in the high single-digit to low-teens trillions—well below $20T. (crfb.org)

4. Comparison to U.S. GDP and possible source of the $20T figure

   • U.S. nominal GDP in 2020 was about $21–22T. (srv1.worldometers.info)
   • Thus, the combined support of roughly $10T is around 45–50% of one year’s GDP, not “one times U.S. GDP.”
   • A roughly $20T number does match some estimates of global fiscal + monetary stimulus during the early pandemic (about $8T monetary and $12T fiscal worldwide), not the U.S. alone. (talkmarkets.com)

Because all credible tallies of U.S.-only fiscal and monetary COVID-19 support cluster around $10T, roughly half of U.S. GDP, and no reasonable accounting brings the U.S. total near $20T ≈ 1× GDP, Chamath’s prediction that the U.S. “final number” would be on the order of $20T, about one year of U.S. GDP is substantially off.

Conclusion: the prediction is wrong.