Here owning the shares means shares in the demat account of the investor.
After record date, you will have 20,000 shares in hand.This is unlike stock split.So, if you want to avail the bonus, then you must buy the share on or before August.On stock split, the market price will be adjusted as per the ratio of split thereby making it affordable to buy.63 per share for Patni Computer System shares which he purchased on 30/8/2010, the day on which Patni share was 14 cheaper than the previous day; but much to his chagrin.The distribution can be done in multiple birmingham lyrics lotto boyz ways :-.Means you should have sharebalances in your demat account on the Record date then only you will get benefited.Ex-Bonus means you will be allotted a share as Bonus for some quantity of shares of that particular stocks.
But, there are other factors also which decide the share price.
I will explain this with an example.
When bonus share is announced, people buy more share of the company to get the benefit of bonus shares.Contract and its values are adjusted with respect to a factor value.You might see some mismatch into your P/L values until Bonus share sits in your Demat Account.It is seen that the share price increase within days of bonus issue announcement and people make profit out.After the issue, the company will have 4 million shares in market.But, the company's total share in market will also double.After the record date, the price of the share will be corrected, and the share will be available for lesser price in the market.

So if an investor holds 100 shares at the time of bonus then they will become 120 shares.
In India settlement is done on T2 basis, that means after 2 days of the transaction date; hence usually ex-date is one day prior to the record date so that shares bought prior to the ex-date finds their place in the demat account of the.