if the person is disable how could even he/she buy bitcoin and wait to surge then sell or are you talking long term plan which in any case cannot wait by the disable person, what if the person's disable quit on life these generally happen around the world committing suicide when life gives you but shit even normal person committed suicide, then how could bitcoin benefit its owner by this mess?
Disabilities cannot be an issue for bitcoin investment or trading, even a disable person can get profit from bitcoin investment and trading, it just need your time to stay and study the market and should choose a good place for your investment which can in fact increase the chances of your profit in trading and bitcoin investment.