I'm really curious in what Teach did to get a raise in bounty
We know that in chapter 925, his bounty was 2,227,600,000. It was shown a page before the beginning of Wano Act2
We also know that in chapter 956(when Wano Act2 ended), he talked to his men about packing their bags to seize the prize before the marines
And this chapter implies the prize he wanted to get before the marines is actually Hancock's devil fruit, with the events occuring from few weeks ago according to the current timeline, with his bounty now being at 3,996,000,000
So that means that he either got his new bounty between chapter 925 and chapter 956, or he got it on his way to get Hancock's fruit, which indirectly means he did something before heading for Hancock to get a bounty increase
Something unknown to us yet