GM is an excellent company to own for the long term. That being said, outside of a core long term position in it (something like 10% is perfectly fine), we can also trade and profit from volatility, both on the long side (adding trades with trailing stops, and adding to winners) and on the short side (selling calls against our long term longs to profit from corrections).
In this case, after today's news, we see that the daily has flashed a 'Time at mode' uptrend signal with a target at 39.57 that has to be hit before January 31st. Since this uptrend's time duration expires just before earnings, it might be wise to reduce your exposure to GM approaching the target, and date, or to at least hedge your downside to protect profits by selling calls. In the case of earnings sending prices way higher, this would ruin the upside, so, the alternative is to start trailing stops periodically (at least on your non-core-long term positions) to reduce risk.
Good luck!
Ivan Labrie.