Over the past few months I've been trading at cryptsy with a simple strategy.
"BTC rising, altcoins rise higher against BTC. BTC dropping, altcoins drop deeper".
The idea was the volatility of BTC and how that might affect greedy/fearful investors.
People would cash out when BTC is dropping, by their fear. To do that, they need to convert altcoins to BTC, then cash out.
People would be greedy for altcoins when BTC is rising coz those look cheap and likely to outperform BTC.
Especially I traded LTC, XPM, QRK, FST, ZET, DGC.
LTC - Second best. The most reliable among alts.
XPM - 3rd trade key currency at cryptsy. The prime number idea might be mathematically great. Sunnyking might have had good reasons to create another coin.
QRK - MD5 looked secure when it first came out. Double-SHA256 looks secure nowadays, but it may look insecure later on. 9 rounds SHA3 could be spotlighted.
FST - The fastest. Some people don't want to wait at all.
ZET - don't know much, just the chart trend looked good.
DGC - the idea "40 seconds is the best" might be true. although I don't know much about it.
It worked. I was able to increase my total BTC amount just by scalping(couple of hours ~ weeks) altcoins.

But over the few days the principle seems to be broken. I want to find the reason here.
My guess is hedge fund is joining now, they're doing sth complex, too complex for me to understand somehow making changes.

How was my strategy? Why altcoins are underperforming now?