but why they become insolvent if are free?
Although we don't know exactly what's going on with Cryptsy, some possibilities are, in order from least to most scam-oriented:
1. Bad Business Practices: Sloppy accounting, lack of professional standards, poor cost containment. I.e., what happens when an immature person tries to run a company.
2. Bad Trades: In order to make markets, they were taking the other side of customer trades (acted as principal in the transaction). The trades went bad on a large scale.
3. Liquidity problems: They ran into problems settling trades. They ended up with a big inventory of alts that was declining in value.
4. Misfeasance: They "borrowed" from customer accounts to pay ongoing operating expenses, fully intending to pay the customers back. It didn't work out that way.
5. Malfeasance: Assets in customer accounts were expropriated for personal use, possibly with intention of repayment, crossing fingers that they could repay.
6. Ponzi: Despite what was displayed on the website, they didn't really have an inventory of coins. The transactions were faked. When deposits net of redemptions stopped
growing, the music ended, leaving account holders to scramble for chairs (withdraw their coins).