[divbzero]

Yes, it’s curious that the traders didn’t participate in similar trades in subsequent months — appears they may have been shocked and spooked at the outsized bonanza. If this is indeed just a good trade going great, the investigation will hopefully clear their names and they’ll simply get credit for their success.

[goodcanadian]

If you do it once, it may have been an accident. If you try to repeat the success, it starts to look like intentional manipulation.

[Reason077]

If you've just had a $500 million pay day, the action in subsequent months presumably was going to be pretty dull (and not lucrative) by comparison. Maybe they've just decided to take some time off to spend time with their families and think about how they're going to spend it!