Basically if you trade longer term vega (which I wasn't doing) you shouldn't consider yourself too much with historical or implied vol, it's future vol you are interested in, the only reasonable thing you can say is that in the long term vol is mean reversing, but if this helps you in trading vol is a totally other mather ...
Predicting future vol is the most difficult thing, those that know probably won't tell, those that tell are probably only guessing ...
if you can really predict vol you can make a fortune trading vol futures, however few can do this ... so yes I doubt it
it's no secret that when IV change on 1% the price of option can change from 2 to 4 %. How i can extract the profit from this without math indicator of IV?
sorry but this is not an english sentence, I don't really understand what you mean, if you want an answer you have to rephrase your sentence. If implied vol changes by 1 point vega indicates the change in price of the option(-portfolio), not in percentage but in real dollars.
certainly you right. SORRY For example. For option on GAZPROM. IV -25. PRICE-3000 if IV is changed on 26 then the price is changed to 3060-3090. and we see in this get prettier possibility for trading.But we don't the method for measure the IV.
you need an options model, it's possible to calculate (or more precisely let the computer) calculate your IV through the model.