Do you guys consider bitcoin a reliable and stable investment for long term holding(5-10yrs)?
I don't have much information about IRA. But I can say that Bitcoin can be quite profitable if you are willing to keep your money on it for a long period as you said. I think Bitcoin is not very short-term friendly but a good choice for a patient investor.
Bitcoin is not stable investment but a good investment to those who know how to trade and to managed their funds, it is not like you buy and wait then earn, there is a need for work to be able to gain in this investment. It is risky and needs to be very much focus in monitoring it as price varies depending on news and analysis. But unlike other altcoins or cryptocurrency, bitcoin is much safer and stable than them.
Probably I would stick in bitcoin investment because I already know and have experienced in cryptocurrency, in my opinion, bitcoin is only the best investment where you could potentially earn a high profit because of the value volatility. If you observe the market even in short term you could probably earn a big profit already in just a small time.
You could also invest in trading if you know how to trade altcoins in an exchange, you could invest money in a trusted exchange that you choose and then buy altcoins that you think have the potential to increase its price. I might earn a decent amount of profit daily in trading and new projects.