Yes, but there is no specific, black and white list or measure to definitively say you are in business or are not. It is a grey area, to be determined by facts and circumstances in each unique situation. As I was saying, getting a 1099 can initially give the impression that you are operating a business on Ebay, and if you get one but fail to include the info from it on your tax return, when the IRS comes calling, do you think they'll view the income you may have earned from selling a card as a long term capital gain automatically? I don't think so. LOL That 1099 doesn't tell the IRS what you were selling. For all they know, you were selling widgets. So they generally assume the worst case scenario for taxpayers (and the most tax being owed to them), figuring that will get a response and explanations and answers back from the taxpayer.
The IRS actually follows a list of nine different factors they will look at to help determine if you are operating as a business, or if you are really in a hobby. The additional idea of being an investor for tax purposes is fairly new, and hasn't really been formally addressed by the IRS, yet, as sports cards being considered as true investments, like stocks and bonds. The following article lists the nine factors the IRS and their agents follow, which as you'll quickly see, are not yes or no, or black and white, questions or measures.
https://www.thebalancesmb.com/is-thi...a-hobby-397675
These factors are really more for situations where someone in a hobby is trying to be able to deduct the costs and expenses of it against their other income. With the way card prices, especially vintage, have gone up in recent years, most people with vintage collections they've had for years will not be worried about selling at losses. However, look at a modern collector who spent a ton of money on a modern rookie, that ended up being a bust. He ends up dumping it for a big loss, and tries to use that loss to offset his other income on his tax return. Here's where those nine factors can come into play.