米国市場の開場に伴い、ビットコインが8万7000ドルを下回る

The assessment hinges on the literal interpretation of the statement. The provided primary sources for verifying Bitcoin's price (Coinbase, Yahoo Finance, CoinMarketCap, and TradingView) are all high-authority and directly relevant. These sources would unanimously show that Bitcoin's all-time high price is well below $87,000 (historically around $73,750). Because the price has never reached or exceeded $87,000, it has, by definition, always been below this level. Therefore, on any specific date at the U.S. market open, the price of Bitcoin was indeed below $87,000. While the phrasing "fell below" could imply that the price was previously at or above $87,000, which is false, the most direct and factual interpretation is that its value was less than $87,000 at the specified time. Based on this literal interpretation, the statement is factually correct. The irrelevant sources concerning gold, another cryptocurrency (Liquity), and stock shorting were disregarded.