Yesterday XRP was 0.7 $ and now about 0.36 $, and 1 thing you should be aware is XRP devs HOLD most of coins in their hands, When you have most of the coins in the community you can easily Control the market, That how they play dirty game.
The situation of the XRP market before now is not new to a lot of crypto enthusiast and that's why people are advised not to invest in high manipulated and centralized coin like XRP but some people are blind by the innovation of the project whereas it has no genuine benefit to the crypto community but to private companies and their team.
Maybe profit takers are reason why the price dip so low,
Profit taker or not this is how XRP market works and sometime the Dev are reason behind the suddenly dump in price.
Do you have any proof that devs sell their xrp yesterday. According to my source, there is no real information about this issue. To my knowledge, trading or investing always involve risks.
Trading and investment is always involve risks but XRP is not the right coin for any genuine crypto trader will invest in. There are some trends and situations in the market that can be prove by any evidence but previous knowledge and I advice you to do your deep your source so you can know that the XRP Dev holds 65% of all total supply.