If you have been adding to your long positions and feeling nervous as they climb, you are in good shape. Hold.
What do you do if you have missed this move, or if you have more cash to deploy?
Trendlines help frame your buy, hold, and sell decisions.
Look at the below 3 charts. The monthly chart of the SPY shows a continued uptrend.
The weekly view shows an almost 2 year battle between buyers and sellers has resolved to the upside as the SPY makes new highs.
On the daily chart, if you draw trendlines containing the price action, it seems prudent to wait for a pullback to deploy more cash.