Self employed

@LisaS , can you please clarify  "Just be aware that the IRS rule is that if it is personal property that you sell at a loss that you don't get to take the loss but sales at a gain are taxes."?  So if I sell a bike I bought for $800 for $650 via a Venmo payment, I wouldn't get to claim the $150 loss against the $650 income?  But the entire $650 would be considered income and subject to taxes?  Or would I have to sell the bike for more than $800 and then the profit I made on selling the bike for more than I paid for it would be income?  Sorry for being dense but I just don't understand the "sales at a gain are taxes" part of your statement.