I need a Grammar check. Need help

0 I began buying stocks which are best known and had a good performance record. My strategy and stocks I picked have paid off. The graph shows a positive sign in earning money for my first two weeks. After selling all stocks, I started looking for a stock that has a large return in a short period. I noticed a few stocks that have just dropped their price per share and expected that they will go up again. I lost almost 30% of my money with this strategy until I decided to change a new strategy. Finally, I short sell one stock that had a high intraday return. I success with this new strategy and start hunted for another stocks with the same categories which fit my new strategy. Finally, I ended up by gained more than 70% for last two weeks only. My graph going up, down, and up again while the S&P 500 index and t-bill are very stable. 0-