If you want to do that, you need a lot of money, maybe $1milion? Really, really big you need to influence the price, although in a small percentage.
1 million is chump change for these kinds of moves in my head. I believe you need at least 10 million, if not 100 million with a few other individuals. Then you can really move the needle, whereas 1 million may only cause a small intraday swing.
A single person by himself can't move the price of a currency, no matter how much effort he is making. If many people are investing and trust the same currency, then with the help of all the people the price of a currency can move up or down. A currency must have its own properties and benefits so that people feel comfortable while using it, only then the currency can be successful.