A trader works on the floor of the New York Stock Exchange (NYSE) during the opening bell in New York, on May 11, 2026. Angela Weiss | Afp | Getty Images It's official: traders haven't been this aggressively bullish since they were stuck at home with stimulus checks betting on a bounce-back in the global economy. Retail traders are buying calls in Cboe's "Mag 10" stocks – the big seven plus AMD , Palantir and Broadcom – at the heaviest 10-day clip since 2021, according to a report from the exchange. Of new positions opened, 52% were call-buying, and 17% were call–selling.  "Hedgers have thrown in the towel," Mandy Xu, head of derivatives market intelligence for Cboe, said in a call.…