If this downturn is typical, the S&P 500 will lose 13.6% in total, bottom in mid-May and be recovered by September.

The 10% trigger for a correction is an arbitrary, round-number threshold. But it serves as a signal that investors have turned pointedly more pessimistic about the market.

Stock market corrections also tend to serve up opportunities for long-term investors to put money to work. Here are two stocks that look especially attractive right now, both of which are down more than 20% in the past month. Both are top-10 investments in my portfolio and ones I plan to add to if the current prices persist.