Congratulations on that milestone! Most likely, the second $500K will come a lot more quickly. This got me curious, to look at my own records, and here's my data:
12/31/1997: Essentially, zero. The furthest my spreadsheet goes back. I was still recovering from a bad divorce, but by this time started to see a light at the end of the tunnel, so I began to get a bit serious about investing again.
3/30/2010: $500K. So, about 12 years and 3 months to get from zero-500K
2/27/2015: $1M. ~4 years 11 months.
9/29/2017: $1.5M. ~2 years, 7 months. However, I got some help here, with a rather sizeable inheritance from my Dad. Some of it had cleared during this period, but some was still in probate.
9/30/2019: $2.0M. ~2 years. I'm using a bit of creative accounting with this one, though. My investible assets were actually around $1.827M. However, I had bought a house in 9/2018, and the deposit+inspection fees+down payment, if added back in, would have put me over $2M
January/February 2020: I flirted with the $2M barrier a few times, and this is on its own merit, not counting that down payment.
8/31/2020: The first time I hit $2M, during the COVID recovery.
11/30/2020: The first time I hit $2M, and seemed to stay above it for good. I'm now at $2.415M, so with any luck, I'll never see a total that begins with a "1" again. (although $10M would be nice
)
Anyway, congratulations on your $500K milestone, and have fun on your journey!