Effect of Split on F&O positions with Example

Yes Bank goes ex-split in the ratio 5:1 on 21 Sep 2017, that is, 5 split shares 

are issued for every one share held in the Demat account of all eligible shareholders.

Effect on Holdings:

When a stock is split, the share price reduces, in this case by a factor of 5. So if you held Yes Bank shares at an average price of Rs.1600, the price of each share after the 5:1 split will be 1600/5 = Rs.320. Your share price gets divided by 5.
Please note that when a stock splits, it’s face value reduces. Here, Yes Bank face value reduces from 10 to 2 and the number of shares increases 5 times. But since the price of each stock reduces by 5 times, your investment value in Yes Bank remains the same.

P&L of holdings:

Your P&L for Yes Bank holdings will show an artificial drop of about 80% on the ex-date of 21 Sep and the record date of 22 Sep. The split shares will be credited to your Demat at the end of the Record date of 21 Sep and it will be visible in your Kite holdings from 25 Sep which is a Monday.(Since 23 Sep and 24 Sep is the weekend).
You will receive an SMS from CDSL at the end of the Record date when your split shares are credited to your Demat.

Effect on F&O positions:

Option strike prices are divided by the factor of 5. The old strike price of 1860 becomes 372, 1880 becomes 376 and so on. The F&O lot size is multiplied by the factor of 5. The old lot size of 350 will be revised to a new lot size of 1750.
The future and option prices are divided by the factor of 5 to maintain the same contract value as of before the bonus issue.