As you know Facebook announced their own cryptocurrency LIBRA but various legislation needs to complete before launched, so after launch can buy but this will be stable coin and will not affect BTC price.
Directly it won't, but indirectly it will, once people get educated with what is libra and eventually use it, they will be introduce in the crypto market and they will surely know about BTC which is a good investment, not only that, this success of Libra will also become a great help for altcoins to recover as investors would certainly touch them knowing they are so much undervalued.