What is valas? Is that some non-English term for fiat and traditional currencies or what are we talking about?
Yes, it's Indonesian. Forex is the short version of Foreign Exchange which in English means Foreign Exchange, and is commonly known as Forex. Check:
https://en.wiktionary.org/wiki/valas.
we all know no one can controls the bitcoin price because bitcoin isn't like bank, stock and valas. but if the whales owned 51% of bitcoin, can do it?. if happen, does decentralization not exist?
This thread is actually pretty much the same as fennic's thread:
Why We People Cannot Think Like Whales. The whale (as you call it) will not sacrifice his money or bitcoins just to control the price. But they really love people who think like that.
I don't think users with huge amounts of Bitcoin (you call them Whales) play Bitcoin price with theirs; it's too risky. But they announce their investment amount and then make statements in the media to control people's minds. So actually those people are stuck with their own thoughts, with their speculations, and with the graphic analysis they make.