Isn't speculation and volatility a problem for Bitcoin?
Logically, it should look like a problem but in reality, that's the charm of bitcoin. Speculations and high volatility are linked with each-other (well, volatility alone sticks with bitcoin). This is the real reason why bitcoin is a popular investment option. Just see, one day you can wake up and see 20% growth on your invested capital. If you catch the good moment of fall and open short position in futures trading, even if there is 30% decline in bitcoin's price, you can wake up with 30% profit and even more bitcoins than before.
You want stable coins? There are USDT, BUSD and others. But they aren't popular in crypto world, so you know now.