One rule of momentum investing says that growth stocks that can hit new highs, even when the broad market is weak, are likely to do even better when the pressure comes off the broad market. Think of it like a coiled spring; as soon as the market’s pressure eases, the coil explodes higher. Many growth stocks do something similar. So last week, as the broad market was tanking, I ran a quick screen, and found a handful of resilient names. Most interesting to me was the strength in healthcare stocks. In effect, investors are now saying that with the...