The core quantitative claim — Chicago PMI of 62.7 in May 2026, a +13.5 point jump from April's 49.2, highest in over four years — is independently confirmed by Trading Economics (citing ISM), Mace News via TradingView, and FXStreet. The 'since March 2022' wording differs slightly from other sources' 'since January 2022' / 'early 2022', but both refer to the same approximate timeframe. The auxiliary superlatives ('largest monthly gain since 2020 pandemic recovery,' '2nd-largest in index's history since 1967') were only directly stated by the Kobeissi Letter post and not independently confirmed in fetched sources, though they are plausible given the magnitude of the move. Overall the claim is likely true with high confidence on the headline figure and medium confidence on the historical-ranking superlatives.