Bitcoin's price has surged past $50,000 for the first time since December 2021, marking a 17.5% increase over the past week. This rally is notable for occurring without the typical retail trader FOMO (fear of missing out) and the use of high leverage, which is often seen in cryptocurrency markets. The increase can be partially attributed to inflows into spot Bitcoin exchange-traded funds (ETFs), which have seen significant growth, surpassing $10 billion in assets in less than a month. Major mutual fund managers like BlackRock, Fidelity, and ARK 21 Shares have launched these ETFs, contributing to the bullish sentiment. Despite the rally, there's a lack of excitement among retail investors, as indicated by stagnant Google searches for 'buy Bitcoin' and stablecoin demand metrics. However, the long-to-short net ratio of top traders has increased, suggesting a bullish outlook among whales and arbitrage desks. The rally's sustainability hinges on continued inflows into spot Bitcoin ETFs, amidst macroeconomic uncertainties and potential shifts in investor preferences due to changes in the U.S. Federal Reserve's interest rate path.