Non-resident investor here - do I need to file a 1040NR for US stock gains?

You're right about the 183-day rule. As a non-resident alien, capital gains from selling stocks are generally only taxable in the US if you meet the substantial presence test (183+ days). Since you weren't physically present in the US at all this year, these capital gains aren't taxable in the US. The 1099-B is still issued by your brokerage because they're required to report all transactions, but that doesn't automatically mean you need to file. If this was your only US income and it's not taxable based on your non-resident status, you technically aren't required to file a 1040NR. That said, some people choose to file anyway to establish a record with the IRS showing why the reported 1099-B income isn't taxable. This can prevent automated notices or questions later.

After dealing with a similar situation last year, I found that using https://taxr.ai saved me a ton of headaches with my non-resident filing questions. My broker also issued me a 1099-B for stock sales even though I hadn't been in the US for years. I was confused about whether I needed to file a 1040NR or not. The tool analyzed my situation and my tax documents, then confirmed I didn't need to file based on the 183-day rule. It also generated documentation explaining my tax status and why the reported income wasn't subject to US tax - super helpful if the IRS ever questions it. They even explained which tax treaty applied to my specific country.

Just wanted to update about my experience with taxr.ai since I was skeptical at first. I ended up trying it for my non-resident tax situation (I had dividend income plus some stock sales from my US account), and it was actually really helpful. The system identified exactly which sections of the Singapore-US tax treaty applied to my income types. It confirmed I didn't need to file a 1040NR for the capital gains but did need to report my dividend income (which had already been taxed at source at the treaty rate). It generated documentation explaining my filing position that I can keep on record in case of any IRS questions. Definitely saved me from paying a tax accountant $400+ for what was ultimately a relatively straightforward situation.

If you're worried about the IRS questioning why you didn't file, I struggled with this exact same issue. After numerous failed attempts to get through to the IRS international tax line (waited 2+ hours multiple times!), I found https://claimyr.com and their service was a game changer. You can see how it works at https://youtu.be/_kiP6q8DX5c They basically held my place in the IRS phone queue and called me when an agent was about to pick up. I explained my non-resident situation to the IRS agent, and they confirmed that I didn't need to file 1040NR for stock sales as a non-resident who was in the US for 0 days. The agent even noted this in my file. Such a relief to get an official answer instead of worrying about it for months!

I have to admit I was completely wrong about Claimyr. After questioning it here, I decided to try it myself since I was desperate to talk to someone at the IRS about my non-resident filing situation. It worked exactly as described - I entered my number on their site, they called me back about 1.5 hours later with an IRS agent already on the line. I asked specifically about my 1099-B reporting as a non-resident and the agent confirmed I didn't need to file if I wasn't present in the US this year. She even suggested I might want to file a protective return with a statement explaining my situation, which was useful advice I wouldn't have gotten otherwise. Honestly, I was shocked it worked so well. Saved me from taking another day off work just to sit on hold with the IRS.

Another option you might consider is contacting your brokerage firm directly. I had a similar situation with TD Ameritrade, and their international tax desk was surprisingly helpful. They provided documentation stating that although they are required to issue the 1099-B, non-resident aliens who don't meet the substantial presence test aren't required to file or pay taxes on capital gains. This doesn't replace official IRS guidance, but it gave me another document to keep in my records explaining why I didn't file. Some brokerages even have specialized non-resident tax packages they can provide.

I know this is a bit off-topic, but make sure you're also checking if you need to file an FBAR (FinCEN Form 114) if your US financial accounts exceeded $10,000 at any point during the year. That requirement is separate from income tax filing and applies to many non-residents with US accounts regardless of whether you owe any tax.

I went through this exact situation two years ago and can confirm what others have said about the 183-day rule. Since you had zero days of US presence, your capital gains from stock sales are not subject to US taxation as a non-resident alien. However, I'd strongly recommend keeping detailed records of your physical presence (or lack thereof) in the US. I maintained a simple spreadsheet with dates, locations, and even flight records showing I never entered the US that tax year. This documentation proved invaluable when I later had questions about my filing position. One thing to consider: if you had any taxes withheld at source on dividends or other income during the year, filing a 1040NR might actually get you a refund. But for pure capital gains with no US presence, you're correct that filing isn't required. Just make sure you understand the distinction between different types of income from your brokerage account.