"Cutting off losses" means not to allow losses to amplify indefinitely, to rationalize losses, and to have a relatively reasonable range for stop loss.

"Let profits run" means that after controlling the reasonable stop loss space, do not blindly worry about the market trend. As long as the stop loss is not hit, hold with peace of mind and let the market tell you by itself. How much profit can you make, rather than guessing how big your profit is. But there are certain conditions for holding. As long as the holding conditions are not violated, you can hold it with peace of mind.