Probably some sort of tax trade. i.e. the put buyer will exercise and take a long term gain on some stock up to $20.00 and a short term loss on the premium.
I'm looking at 43,000 contracts executed at $10 yesterday but my stone tool could be broken. There was no time value on this trade and there were better ways to relieve a tax situation IMO. This is a synthetic long position with a credit to the account holder (for the seller), although the aggressor seems to be the buyer here. This is a very interesting situation. Someone was on ISE bidding for another 1200 thoughout the day.
I show 52515 JNPR Jul 20 Put contracts traded yesterday. As of market open yesterday, the OI was 3233. I guess we should see an open interest change today. Somebody is taking a pretty big position. I suppose it could be for tax purposes, as pabst suggested. However, wouldn't this be a "constructive sale"? The date of the sale being the day the option was bought. Just wondering.