Will an oracle superintelligence be developed before a general superintelligence?

An oracle (Wikipedia, Lesswrongwiki) is a theoretical capability-constrained artificial intelligence (AI) limited to answering questions. An oracle would plausibly be easier to safely implement than a general AI, and it may help to solve the safety issues associated with general AI. Therefore, a reasonable case can be made for developing an oracle first, even if a safe general AI seems feasible. However, an oracle would have considerably less (though still large) upside than a general AI, so it may be less appealing to investors.