It seems it is the only altcoin at the moment that has not been very effected by the ups and downs of the cryptomarket. Since the bubble, every other altcoin has been sliding down, it has been either rising in value or staying consistent.
Novacoin has a market maker who has been guiding the price. The word that describes the amount of XRP available for the market to trade is the float. The market cap may be $1B+ but I'd be surprised if the float is even $2MM.
http://www.investopedia.com/terms/f/float.aspI suppose some may use their BTC position to go into alts but I'd recommend only putting new outside money into them if you feel compelled to gamble. I say this in spite of having some recent misgivings about the level of electricity wastage under a pure proof of work currency.