Investment in Commercial Bank is less risky compaired to other sectors. A new investors need to learn many things in the beginning. Investing in risky stock at the beginning may cause you a huge loss. Also, start your investment with a less capital. Do not invest you entire capital at once. If you start your investment journey with small capital and suffer loss in future then you can minimize your loss through investing in the same stock in a decreased price.
For example : If you purchase 100 units stock of X company for Rs.450 and the stock starred to decrease and reached to Rs. 300 then you can further purchase another 100 units of the same share for Rs. 300. Now, cost of your 200 units of share will be Rs. 375.
Again, if the share price increases and crossed the price of Rs. 375 you can book profit. For the such averaging and minimizing the risk you should not invest you entire capital at the beginning.