I may be naive, but I do not see Carl just rolling over and giving up. He know this company is worth a lot more than $13.65 and it is worth a fight. I would guess he has had many conversations with BX and SW and they are working on something. Perhaps it's a larger offer, perhaps it's something that forces Dell to pay up to avoid a lengthy legal battle. Either way,I think the stock goes higher.
Interesting that after hours someone bought 10M shares. Yes I know there was also a seller, but someone doesn't drop 140M on a guaranteed loser like this would be if Dell gets to steal the company. Just doesn't make sense. I suspect that whoever bought is someone in the know - perhaps Icahn or BX.
Stocks are traded meaning bought and sold. You can't have a buyer without a seller (besides arguably an IPO). The fact that 10mil shares were traded after hours in one block which was over 37% of the days volume and were at the closing price it is probably safe to assume they were not only bought but at market price too. This means someone wanted in badly in my opinion.