The price per Bitcoin dropped below $45 thousand per coin, prior to the opening of the U.S. financial market this week. There are a few possible reasons for the crypto decline including this week’s upcoming two-day Federal Reserve meeting where it’s expected that the Fed will talk about slowing its liquidity policy, calls for more crypto regulation, and a possible U.S. tax hike to pay for trillions in proposed social programs from Democrats in power.

Another contributing factor could have been the fact that last Friday represented a “triple-witching” day. That’s where options – contracts to buy or sell assets on a future day at a certain price – expired across three different asset types: stocks, stock indexes, and stock index futures. Friday’s expiry date involved trillions in traded assets under contract.

Lastly, global financial markets are responding negatively to news out of China that the world’s largest real estate asset manager – China Evergrande Group – could default on loan payments this week following new laws in that country restricting the size of real estate holdings. Evergrande stock dropped 10% in Monday morning trading for a 85% total decline from the start of the year.

Whatever the catalyst for this latest crypto sell-off, the overwhelming majority of top-20 cryptocurrencies have been in the red over the past 48 hours, with the only crypto assets in the green being stablecoins. Despite the slide, the President of El Salvador took to Twitter today to announce that the country was adding to its Bitcoin bags.

Earlier this month, El Salvador officially rolled out Bitcoin as legal tender within its country. Despite a few hiccups at the launch, and pockets of protests against the digital monetary move, the country has noted that more than one million residents have downloaded its digital wallet, Chivo since the formal adoption of Bitcoin.

This could be a big week for cryptocurrencies. A weekend story in the New York Times suggested that the U.S. Federal Reserve sees stablecoins as a significant threat to the economic vitality of countries around the world and that regulation is coming. A formal announcement against stablecoins during the Fed meeting this week could spur further crypto declines.