I bought BTC at $250, the it dropped to $80. It rose to $1000, I bought more BTC, then it dropped to $200. Then it rose to $3000 and I sold it all for a profit.

I bought BTC at $250, the it dropped to $80. It rose to $1000, I bought more BTC, then it dropped to $200. Then it rose to $3000 and I sold it all for a profit. The bottom line is if you believe it in the long term and have the patience to accept any medium term losses, it is fine to put your foot in after a run up. Maybe invest 10% of what you're willing to lose now, which can be nice to get the trust of exchanges early, so when you can buy more your daily limit will be higher. It takes some days to open an account so you might also want to do it weeks before you want to buy. When it inevitably crashes you can buy more. I recommend averaging in, say 10% a month over a year, you will get a range of low and high prices.