It's caused by bitcoin dump and that was decreasing the hype for the ADA smartcontract or the hype already happened, don't you see the big increases that happened with ADA since last month? that was proving if the hype for the ADA smartcontract was a real thing and i think that you can't expect the hype will be last long. you must also try to see the quarter chart of ADA and i guess that was answering your question.
https://coinmarketcap.com/currencies/cardano/

The price has already doubled since last month and the hype has already happened. it seems like that you're missing something from there. Just take a look at the chart.