Bitcoin BTC$61,004.20 likely has further downside ahead before the current bear market runs its course, according to 10x Research founder Markus Thielen. Thielen's call centers on the recent strength of the U.S. dollar, which historically acts as a headwind for bitcoin. The outlook has been reinforced by the Federal Reserve's hawkish turn under new Chair Kevin Warsh. Markets are increasingly debating whether the Fed's next move could be a rate hike rather than a cut, a backdrop that has supported the dollar and weighed on assets.