Stocks closed out the week with a bang ... but not in a good way.

The Dow finished Friday's session down 665 points. The sharp declines came just two days after January trading capped off the best monthly stock performance since March 2016. This week is now the worst in two years.

Here are three reasons why the market tanked on Friday.

Bond Yields

The U.S. 10-year Treasury yield jumped to 2.85% after the jobs report Friday, tallying a four-year high. Bond yields have spiked this week as investors digest signals of faster inflation in some of the world's largest economies and the impact that could have on growth and interest rates. Rate hike pace concerns were exacerbated by faster wage growth stats this week, too.

Tech Earnings

Tech earnings are often a go-to for when investors need a little optimism. But this week, tech earnings were disappointing. Apple Inc. (AAPL) stock fell 3.5%, Alphabet Inc. (GOOGL) stock fell 4.9%, Facebook Inc. (FB) stock fell 0.6% and Microsoft Corp. (MSFT) stock fell 2%. Read more about tech earnings this week here.

Apple, Alphabet, Facebook and Microsoft are holdings in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio . Want to be alerted before Cramer buys or sells these stocks? Learn more now.

Trump Memo

Could investors be waiting for the other shoe to drop? It's possible. With the approval of President Donald Trump, the House Intelligence Committee released a disputed GOP memo alleging the FBI has abused its surveillance authority. While there's no direct tie to the stock market, concern over Washington instability could be sending investors away from risky assets, including stocks.

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