Bitcoin crossed $81,000 during Asian trading hours Tuesday — its highest level since late January — extending a 5.3% weekly gain from $79,000 at Monday's U.S. close, even as Brent crude held near $113 and U.S. destroyers transited the Strait of Hormuz under reported coordinated threats. According to CoinDesk, Nomura's Laser Digital flagged a build-up of low-cost call ratio structures underneath the market, with traders buying modest upside calls financed by selling deeper calls — a setup that benefits if BTC grinds higher. A flip in BTC's risk reversal from negative to positive would be the first confirmed signal that options markets have shifted from defensive to constructive.