In that situation, I would classify all of them as inventory. Inventory is generally simpler on the tax return and offers better opportunities to deduct unrealized losses. In other asset classes, unrealized losses should sometimes be recorded in accounting, but they cannot be deducted for tax purposes. In inventory, however, unrealized losses must be deducted item-by-item (at least, this is what our auditor explicitly required).
And portfolio turnover doesn’t need to be particularly fast. Indeed, goods can remain in inventory for years as long as they are current and do not expire.
The main principle, of course, is that they should be placed in the section of the balance sheet that best reflects their true intended use. For example, my own company has a couple of unlisted investments in fixed assets because there is no marketplace for them, and they cannot necessarily be easily divested. Determining their valuation is also somewhat difficult, so they are there at their purchase prices. All listed and other easily liquidatable investments (including crypto) are in inventory.