You can also use @tipU to invest - which works kinda like a investment fund. Just send SBD or STEEM to @tipU with memo: invest which will be treated as sp delegation.
If you want your money back, just send 0.001 SBD to @tipU with memo: refund
Please feel free to test it, more info should appear below in a moment: help
RE: @tipU Delegations Profitability Check: 17.10.2018