I would consider this not a correction but more like a redistribution happening in the crypto market, due to the massive amounts of altcoins out there now. We should not forget that bitcoin is oldest on the market, but new players appearing with an increasing rate, and the total amount of new money flowing into crypto is distributed over all the different crypto currencies. Some of them very promising other just junk, but still the money is spread over all these coins, instead of flowing into bitcoin alone.