Check your inbox for email from stellar.org, you may be sitting on XLM
TL;DR: If you signed up for Stellar back in 2014 you were automatically given 6000 XLM that you can claim and transfer to your wallet.
Stellar has been receiving a lot of hype recently and earlier this week Stripe announced that while they are dropping Bitcoin support, they may add Stellar instead.
Shortly after Stellar posted their roadmap for 2018 and the hype train was real.
I haven't really been following Stellar that much but if there's one company that knows a lot about payments and the underlying problems, it's Stripe. They have also provided seed funding to the Stellar nonprofit organization.
As it turns out, if you signed up for Stellar when it was announced in 2014 you were actually granted 6000 XLM for free. I searched the inbox for emails from stellar.org and lo and behold, there it was.
I had completely forgotten about even signing up in the first place but I logged in and could immediately claim my free XLM. At today's exchange rate they are worth $3716, that I didn't even know I had.