President Donald Trump's trade war is creating significant uncertainty. Equities plunged following his decision to impose tariffs on almost every country, then soared after he announced a 90-day pause on his expanded tariff plans. It's challenging to predict which way the market will move next, but in times like these, it helps to invest in companies that look likely to perform well in the long run. Consider the case of TransMedics Group (TMDX 1.24%), a medical technology company whose shares have declined ...