many bitcoin price manipulation was a pretty big play.
therefore making huge profits but there are still problems as members of this makes bitcoin bitcoin prices do not ever fall from the previous lowest price.
i think it was possible in past but now as time pass and bitcoin is becoming more and more popular and the number of bitcoin users are increasing continously therefor it is now becoming difficult to manipulate the price of bitcoin
In real life, though, this is nowhere near the case
If the number of Bitcoin users increases (and this is a big if on its own), that doesn't mean that the possibilities for price manipulation diminish. In fact, they could even grow. You seem to implicitly assume that the new users will be using their bitcoins for trading or whatnot, but this is not necessarily so (I'd rather say it is highly unlikely). If they just stash their fresh coins away (which some obviously do), these coins can be considered as left for dead (at least, for the time being). Therefore, the total number of coins circulating in the market is likely to decrease over time, but that contributes to price manipulation, not takes from it (a rule of thumb, less coins in the market means more price manipulation)