Shares of Best Buy (NYSE: BBY) fell 15.8% in May. At first, Best Buy shares fell around 5% on May 13, 2019 when China introduced plans for retaliatory tariffs in response to the Trump administration's decision to increase U.S. tariffs. Best Buy stock dropped another 5% on May 23, 2019, when the company released its first-quarter 2019 results – the results were not necessarily bad. Quarterly revenue climbed a small 0.4% year over year to $9.14 billion, helped by a better-than-expected 1.1% increase in comparable-store sales. That created a 24% increase in adjusted earnings per share to $1.02. Best Buy investors know that the broader market also fell hard last month - including a nearly 7% decline from the S&P 500. This is due to escalating trade wars and a possible macroeconomic slowdown. At least, the shares are still up more than 16% so far (at June 8) in 2019. Best Buy's drop last month could feel much less serious.