The clearest statement of what these products are not comes from the trusts themselves. A large spot bitcoin ETP's annual report on Form 10-K states that "the Trust is not registered as an investment company for purposes of U.S. federal securities laws and is not subject to regulation by the SEC as an investment company", and that "consequently, the owners of Shares do not have the regulatory protections provided to investors in registered investment companies". It then names the specific provisions of the Investment Company Act of 1940 that do not apply, including those that limit transactions with affiliates, prohibit the suspension of redemptions except in limited circumstances, and limit sales loads.
The commodities side is stated just as plainly. The same filing says the trust "does not hold or trade in commodity futures contracts or any other instruments regulated by the Commodity Exchange Act", and that "the Trust is not a commodity pool for purposes of the CEA". The consequence follows: share owners do not receive the disclosure document and certified annual report that a registered commodity pool operator must deliver, and do not have the regulatory protections provided to investors in commodity pools. So the product sits outside two regimes a buyer might assume it sits inside, and its own filings say so.
What that leaves is the ordinary machinery of a listed security. The shares are registered under the securities laws, the sponsor files annual and quarterly reports, the shares are listed on an exchange that applied for and received permission to list them, and the trust publishes what it holds. Custody of the underlying bitcoin sits with a custodian the sponsor appoints, which is a real dependency rather than a formality, and the risk factors in these filings discuss it at length.
On tax, the honest answer is that the trusts themselves flag uncertainty. The risk factor summary in one such filing states that "the treatment of digital assets for U.S. federal, state and local income tax purposes is uncertain". This site therefore states no rule about the character of gain on these shares. That is a deliberate contrast with metal products, where the position is settled and disclosed: a physically backed gold trust's filing states that shareholders are treated as if they directly owned a pro rata share of the underlying assets and that gain on shares held more than a year is generally taxed at a maximum rate of 28 percent as a collectible. Bitcoin is not a collectible under the statute that defines the term, so the analogy does not carry over, and the answer for any particular product belongs in that product's own tax disclosure.
There is one structural feature of exchange-traded products worth knowing because it explains why the market price tracks the asset at all. FINRA describes ETPs as offering two layers of liquidity: transactions with the issuer in the primary market through a creation and redemption mechanism involving broker-dealers and large blocks, and transactions on an exchange in the secondary market, where the vast majority of retail activity occurs. The primary-market mechanism is what gives professional participants an incentive to close any gap between the share price and the value of the bitcoin behind it.