I think your strategy in the case of VeChain is ill-advised, and here's why: if there is a pump prior to the March 20 snapshot, it is because of people trying to achieve (X) Node status. However, as the VeChain rules state, if afterwards your balance dips below the required amount, you lose this status immediately (and, in the case of an X Node, forever). Therefore, it makes no sense to buy more VeChain only to sell it right after you have achieved the Node status. Especially since this is a one time opportunity in the case of the X nodes.

There might be some people like you, trading on this thesis, that make this scenario play out anyway though. But in my opinion so far the VeChain team have been VERY professional, and I am convinced they deliberately structured this program this way as to avoid a pump and dump happening.