Thursday is ex rights so at the start of trading any shares you purchase no longer come with rights to the entitlement, the seller would keep those rights.
I also think you are confusing the rights (to the entitlement) mentioned there with the options maybe. The offer is renounceable, so after the ex day you can then trade your rights to buy the 5 for 2 entitlement on a deferred settlement.
BLK Price at posting:
7.5¢ Sentiment: Sell Disclosure: Held
