What happened

Shares of Best Buy (NYSE:BBY) fell 15.8% in May, according to data from S&P Global Market Intelligence, as the impending impact of tariffs overshadowed a strong quarterly report from the electronics retailer.

To start, Best Buy shares fell around 5% on May 13, 2019, alone, when China introduced plans for retaliatory tariffs in response to the Trump administration's decision to increase U.S. tariffs (from 10% to 25%) on $200 billion of imported Chinese goods. As fellow Fool Tim Green pointed out at the time, the development effectively threw a wrench in Best Buy's previous full-year outlook, which assumed the impact to its cost of goods sold would be limited by U.S. tariffs remaining at 10%.

A Best Buy storefront.

IMAGE SOURCE: BEST BUY.

So what

Best Buy stock dropped another 5% on May 23, 2019, when the company released its first-quarter 2019 results -- but that's not to say those results were bad.

Quarterly revenue climbed a modest 0.4% year over year to $9.14 billion, helped by a better-than-expected 1.1% increase in comparable-store sales. That translated to a 24% increase in adjusted earnings per share to $1.02, trouncing analysts' consensus estimates for $0.86 per share.

But Best Buy followed by merely reiterating its full-year outlook, which calls for enterprise revenue of $42.9 billion to $43.9 billion, and adjusted earnings per share of $5.45 to $5.65. Sure enough, according to Best Buy CFO Corie Barry, that reaffirmed guidance "balances our better-than-expected Q1 earnings, the fact that it is still early in the year and our best estimate of the impact associated with the recent increase in tariffs on goods imported from China."

Now what

Of course, Best Buy investors can take some solace knowing the broader market also fell hard last month -- including a nearly 7% decline from the S&P 500 -- due to wide-reaching concerns over escalating trade wars and a potential macroeconomic slowdown.

Viewed through that lens, at least, and with shares still up more than 16% so far in 2019 as of this writing, Best Buy's drop last month feels much less severe.