Factors affecting cryptocurrencies market

Factors resisting rise in prices:

1. ICOs - Each new currency potentially drains value out of existing currencies.
   It does not decrease the entire cryptocurrency market as a whole, but it may devalue currencies existing prior to its inception.
2. Reduction in central banks' balance sheets - I doubt its happening, and I doubt more its happening in a magnitude which will hurt cryptocurrency prices, so it should only be considered as a theoretical possibility.
   Whenever an amount of a currency decreased, it was always temporary, unless a currency disappeared, and then its value went to 0 which (also) supports a rise in price in its own terms.
3. Holders needing to use their cryptocurrency in order to buy other stuff, to cover debt, pay taxes/fines, or simply having to sell their cryptocurrency.

Factors supporting rise in prices:

1. Disowning of existing (crypto)currency - not expected to balance #1 from above, but offsets a part of it.
2. Increase of central banks' balance sheets - more sovereign/fiat cash means an upside for all prices, cryptocurrencies included. Historically fiat/sovereign currencies increase over time, which makes this factor realistic and #2 of above list much less for long term.
3. People losing access to their accounts/wallets - decrease in amount of available commodity increases price of remaining available commodity.
   Hacking into accounts and stealing their cash might happen and whenever it happens to a forfeited account, it helps offset this phenomenon.

• There is also an internal competition within the cryptocurrency market between different cryptocurrencies, but as an aggregate this phenomenon is not effecting the worth of the entire market as a whole.