My method, as described in my book Building Wealth in the Stock Market is that of an end-of-day investor. This means that most often I only check the market when the data comes down after it has closed. I make my decisions then and act on them next morning.
That is the norm. However, the reality can sometimes be different. If I see one night that the price has already fallen very close to my sell-stop, I may check the market next day mid morning and mid afternoon and act on the sell-stop immediately if it has been violated. The same thing may apply if overseas markets have fallen very heavily overnight. That said, it would be rare for me to check the market during the day – maybe a dozen or so times a year.
The reason I act in this way is that I invest in trends, as described in the book. I have three sell-stop signals. These are based on the intra-day low, so once a sell-stop has been violated, I am bound to sell, no matter where it closes. I mean that too- I sometimes execute a sell-stop above the sell-stop level. The logic for this is what drives my investment plan. I am a trend investor. My three sell-stop signals indicate that the trend may be ended. So, I act on it. If the trend re-asserts itself later, as sometimes happens, I will consider re-entry as a new trade on its merits.