However, outside of these traditional assets, there lies great opportunity for diversification by purchasing and holding assets such as real estate, promissory notes, tax lien certificates, private placement securities, gold and even Bitcoins. No individual, company or institution owns the bitcoin protocol as it is an open-source project. All keys are needed in order for an authorized transaction to take place. Calling all HuffPost superfans! Cumulatively, those fees could negate the tax advantages offered by IRA accounts.