when to sell a stock

SELLING A STOCK

1. IF the sock has p/e of 15 while the similar quality companies in the industry have 10-13 p/e's
2. no insiders bought shares in last year
3. no new product are being developed
4. the company paid too much for their acquisitions
5. sales are downing year by year
6. increasing level of debt ratios
7. final demand for their product slow down
8. lack of free cash flow
9. lack of innovation in its product 
10. its cost more than its earnings