The reserve funds is set as an alternative available whenever an investor wants to use it, definitely some might choose to invest with their reserve fund obviously they’ve their reason so long as they can afford replacing the money back.
Sure reserve funds is set as an alternative for investors, but it shouldn’t be used for investment. If you decide to make use of your reserve funds to invest just because you know you can replace it back, what if their is an emergency, and the reserve funds which you are suppose to use in solving the problem have been used to invest in bitcoin, and you haven’t replaced the reserve funds back yet? You won’t have choice than to just fall back to the coin which you bought, and you won’t have choice than to just sell it.
So I still recommend not to make use of reserve funds to invest even if you know that you can replace it, because you might not have replaced it yet before the need will arise, which will be another problem, things like this do always affect our investment plans.