What happened

Here we go again.

News of a new coronavirus variant in South Africa sent stock markets reeling on Friday, with the S&P 500 falling 2% through 12:22 p.m. ET and the Dow tumbling 2.5%. Even financial giants like Visa (V 0.33%) and Mastercard (MA -0.07%) weren't immune to the pain, either. Visa shares are currently down 2.7%, and Mastercard is down 4.7%.

Red coronavirus nodules tracking a stock chart down.

Image source: Getty Images.

So what

Does this make sense, though? I mean, on the one hand, sure, coronavirus couldn't have picked a worse time to rear its ugly head again. South Africa literally dropped this bombshell on the markets just as American consumers were digging into their Thanksgiving turkeys Thursday, and fueling up to go out and begin their Black Friday shopping.

For a stock market driven by consumer spending, this was truly horrible timing.

Now what

On the other hand, consider how investors are reacting today: They're selling off Visa and Mastercard shares, two of the companies most favorably positioned to benefit if consumers once again retreat to their keyboards to shop online with credit cards rather than go out to physical stores where they might be tempted to -- horrors! -- pay for their purchases with cash money.

Even in a worst case scenario, in which consumers panic and stop using their cards to patronize services that require in-person contact, remember: We've seen this movie before, and what happened last time is consumers just bought goods instead of services. As a result, in the heart of the pandemic in 2020, Visa's revenues only declined 5% in comparison to 2019 levels, and Mastercard revenues declined less than 10% (according to data from S&P Global Market Intelligence).

And both companies bounced right back to do more business in 2021 than they did in 2019.

Long story short: The discovery of a new coronavirus variant isn't the end of the world. Although admittedly, I find Visa stock more attractive at its valuation of 36 times earnings today than Mastercard at 42 times earnings. Both companies are survivors and have business models that have proven to work well in pandemic times.

I see no compelling need to sell either one today.