Personally, I think it's because a lot of people in the altcoin market are short-term oriented and will sell some of their BC to try their luck on newer coins with more hype when they think BC won't rise right away. A lot of people sell not because they think BC won't rise, but because they think it won't rise that same day. This adds some selling pressure but also means there are a lot of people on the sidelines who believe in BC and will buy strong as soon as there's a clear uptrend. I think it's for that reason that when BC uptrends it tends to be fast and vicious.

Markets aren't always rational and they act different for top coins. Every piece of news won't give us a rise, but I think over time they add up and then eventually people see BC as undervalued, causing a swift upwards correction.

But I'm long on BC and not much of a short term / day trader. I think it's a dangerous game selling now.. IMO we're undervalued now and at or close to the bottom of this trading cycle.