Bitcoin (BTC-USD) is struggling to gain momentum as it heads toward its worst month since June 2022. As prices hover around $91,000 per token, or roughly 28% off their October all-time highs of more than $126,000, the cryptocurrency's problems don't appear to be easing. And three key challenges for bitcoin have emerged as investors and strategists dig through the rubble of this month's decline. First, outflows of bitcoin exchange-traded funds (ETFs) for November have reached $3.5 billion, their largest ...