When should I sell my stock and cut my losses?

Eventually, the time may come when I will need to consider selling a long-term losing stock. 
In most cases, if one of my stocks is declining, I would just ignore the market price and keep it until the price reaches my desired selling price.
I am confident in holding my company for the long term because I know that I originally bought a good company at a bargain price.
Also, I went through all of the initial steps of asking myself if “I would hold the company for 10 years if needed.”

In addition, we should remember that “market price” is not the real value of the stock.
Think of this as simply a quoted price that goes up and down.
Sometimes the market offers you a ridiculously high price and sometimes it offers you a ridiculously low price.
Other days, it offers you some price in between.

It is your job to take advantage of the “market price” and buy when you’re offered a ridiculously low price and sell when you’re offered a ridiculously high price.
This same idea can be found in the story of Mr. Market (originally written by Benjamin Graham).
I highly recommend that you read this short story over and over again. 
(I’ve attached a version of “Mr. Market” that was written by Warren Buffett in his letter to shareholders.)

What if the Stock continues to Decline for Multiple Months?
In this case, I would reanalyze the stock and see if it is still a good company at a bargain price.
I would do this with the BTMA Stock Spreadsheet. 
You can also go back to Part 1 of this series on “A Profitable Stock Investing Strategy”, and follow the same steps to re-evaluate the company.
If it is still a good company at a bargain price, I might even buy more of this further discounted stock.
But if something has changed since I originally bought the stock and it no longer has a good company rating, or if it is now overpriced, then I will consider selling the stock.
I would also consider selling the stock if there has been a major and serious change within the company that will have a permanently negative effect on the future growth and profits of the company.

I hope that this information is useful for you. 
-Grant