Investors are hedging against a decline in Bitcoin to levels last seen after election day.The open interest for put options with a strike price of $70,000 is the second highest among all contracts expiring on February 28.Bitcoin has fallen around 20% since Donald Trump's inauguration, due to concerns about inflation and a record hack of the Bybit exchange.Bitcoin fell for a fourth consecutive day, dropping around 5.6% to $83,744, bringing its four-day decline to the biggest since August.