When to sell stock

Since a few years I have been investing in stocks and ETFs. When I do a selection of assets to invest in, I follow a long-term strategy. For this to work out, I try to answer the following questions before doing an investment:

• Do I know the market well enough?
• Do I believe this company will be relevant in 5-10 years from now?
• Would it hurt financially if the investment would be a total loss?

I almost never sold any stocks or ETFs throughout the years, because I was not sure when would be a good time to do so? If I follow through with my long-term strategy, I would almost never sell. But of course, there are circumstances when selling is the right thing to do.

I sell when...

• If I no longer believe that the stocks or ETF I chose grow faster than the market
• The market of the assets performs below expectations / other markets
• When I need liquidity, possibly for another investment with a better return