When BTC reaches $30,000, buy some so that in about 10 years we will know how profitable it is and will ensure your profits are more stable.
It won't take that much years to see how much bitcoin would be worth for retirement. But in less than 10 years, starting today, we're going to see how much gain someone who holds 1 bitcoin by that time.
Even in bearish times, bitcoin is already profitable. It's all up to you how you look to the current market but each market is profitable if it's for bitcoin.