Step 1: You plan to put an offer in on a company, which you know will drive up the share price

Step 2: You buy shares in the company

Step 3: You publicly disclose you will buy the company, driving it's share price up

Step 4: You sell those existing shares now that the price has gone up.

That is trading on insider information.

Insider information isn’t information that only exists in your mind.

If you have no intention to actually follow through and it's a false promise, that's a pump-and-dump. It's securities fraud, but it's not insider trading.

If you have an intention to actually buy and make a good faith effort and fail, that's just business.

Market manipulation is what I meant instead of insider trading. My point was: illegal.

Depends on intentions. The fact that he hired Morgan Stanley to facilitate the privatization process indicates genuine intent.

Ehhh any large play could be considered market manipulation. JetBlue recently offered to buy Spirit, but there’s no 2000+ comment thread on that.