Last week’s market drop on increasing tensions between the U.S. and North Korea, the second-worst weekly performance of the year by the S&P 500, was a great buying opportunity based on a history of past geopolitical events, even ones more serious than this one, says Credit Suisse.

“Geopolitical shocks tend to provide a buying opportunity, unless there is: an underlying economic slowdown, clear cut overvaluation or a monetary tightening,” Andrew Garthwaite, the widely-followed global equity strategist at the firm, wrote in a note at the end of last week.

Garthwaite cites the Cuban Missile Crisis as exemplifying this phenomenon, saying that the similar “but more serious” event sent the market down 7 percent before it recovered losses “within nine days.”

A large geopolitical shock to the market also needs a sluggish economy accompanying it to have a notable affect, Garthwaite claims. The first Gulf War sent the market down 17 percent. Garthwaite says it took 118 days to recover losses from the military shock due to the country then “entering a mild recession.”

The S&P 500 fell 1.43 percent for the week, the most since the week of March 24.

Credit Suisse sees the S&P 500 rising about another 5 percent to 2,550 as it bounce back from this latest shock. Garthwaite says earnings around the world remaining better than expected is the main reason why stocks will continue higher.