Very strange trade...based on the prices paid vs bid:ask, it appears someone sold 1000 APR 13 calls (OI is 1130) contracts and bought 1000 Oct 17 calls (OI is only 110). The only rationale I can find for this strategy is expecting the price to decline short term and then rise later. Perhaps the seller also owns stock, or was closing their long April 13 call position and wanted to use the profits to stay in the game longer term? Very odd, but large enough that it should not be ignored.
How does this sound?
This person bought 1000x 13.00APR calls a while ago, which is why the OI for 13 is 1130. He's made a good profit off of them, but doesn't want the shares. So he is selling those to close, walking away with his $310000, and he's still very bullish long term for IMGN so he is reinvesting about 100,000 to buy October calls.