It's a lot closer to hunting licenses than voting tests. It's certainly true that preventing the unlicensed from hunting means that their rifles, freezers, four-wheel drives, dogs, and grills have less value than someone who is qualified to hunt. Yet hunters and non-hunters almost universally demand licensing because without a minimal set of knowledge, the risk that an individual is a threat to themselves, others, and the viability of the ecosystem, is rather too high compared to the potential benefits of unrestricted hunting.
From a more pragmatic libertarian perspective, one might also worry about the welfare claims that a person who is ill-equipped to make speculative investments and gets wiped out will make on society. One must also consider debts that they will fail to pay if they are forced to declare bankruptcy (one reason why stock exchanges never let you fund your account from a credit card—unlike coinbase). State-managed bankruptcy and welfare may be seen by some libertarians as incursions on liberty but they are also mechanisms that enable a higher degree of risk-taking and potential innovation from the same class of people who are restricted from some risky sorts of investing. Once you make these provisions you have to manage the costs, but its not clear that a classical libertarian prescription of eliminating state-involvement in bankruptcy and welfare and opening up speculative investments to all would improve class mobility.
The test to become accredited demonstrates that a person has the capacity to handle a failed speculative investment and is less likely to need to socialize their losses (obviously bank bailouts are a counter-example to the point I am making here, but that's just how schizophrenic our regulatory environment is).