^^
Who are these
experts of which you speak ... everyone is just guessing ...
Everything is a guess if you want to take it to the extremes but estimating based on experience and historical patterns is far more justifiable. It should be observable that gains are far more likely to occur after halvening then before.
If you consider the actual change itself, a constriction of supply though its increasingly slight now vs the first early halvening. The changes are after the event, each new block gives a lower block reward so only after a year of that change can we say it adds up to something bigger then a tiny amount difference in BTC expected circulation.
Simple advice applicable to almost any market based price is buy the rumor sell the news. If you simply transferred that advice here you would sell the halvening. People who've been around will tell you not to now because most gains will accumulate after in that change. The news of halvening is not news, its been known a while and speculators already included it in the price ahead of the event so this is the rumor type movement.
In BTC what actually matters more is the effect of the news, experience shows its best to wait not jump the gun as if the change, its positive effects are all immediate; that is dead wrong. Its quite fair and reasoned to say a hold now is best.