Here is an example of the difference between property versus currency for tax treatment:
If Evan goes to the store with $200 and purchases something for $55, the transaction is relatively simple. Evan gives the clerk $200 and receives the product as well as $145 back. The product is worth $55 and that will be the adjusted basis (aka the original cost) for the product.
Instead, if Evan has crypto worth $10,000 that he exchanges for a new crypto valued at $10,500, then Peter has a $500 gain. In other words, Evan exchanged an asset that was worth $10,000 and received another asset worth $10,500. That new asset in Evan’s hand is worth $10,500. Presuming it was an arms-length transaction, the general rule would be Evan has a $500 gain that he would need to report on his tax return for the current year. When Evan goes to sell or transfer the new asset, it will be worth $10,500.
As you can imagine, when a person has hundreds, thousands, or even millions of crypto exchanges in a single year — the tax ramifications can be daunting.