SPTX
+$0
2.68M sh
ARCH Venture Partners XII, LLC
10% Owner, Director · SEC CIK 1979548Advertisement
Buy track record
How this insider's open-market purchases have performed4%
of buys now in profit
1 up · 22 down
Avg return since buy−75.4%
Median return−84.6%
Best trade+5.9%
Worst trade−87.4%
Buys scored23 (+2 n/a)
Average return by holding period — separates good entry timing from riding one long winner
After 1 month
+0.7%
57% won · 23 trades
After 3 months
+39.9%
91% won · 22 trades
After 6 months
−7.4%
36% won · 22 trades
After 12 months
+6.5%
65% won · 20 trades
| Date | Company | 90d trend | Buy price | Value | ΔOwn | 1M | 3M | 6M | 12M | To date |
|---|---|---|---|---|---|---|---|---|---|---|
| May 4, 2026 | SPTX | $18 | $19.8M | +21% | +5.2% | — | — | — | +5.9% | |
| Oct 27, 2025 | NMRA | $3 | $5M | +46% | −16.7% | −20.8% | −17.5% | — | −33.8% | |
| Aug 1, 2025 | PRME | $3 | $10M | +95% | −22.8% | +12.9% | −5.9% | — | −31.3% | |
| Feb 15, 2024 | PRME | $6 | $20M | NEW | −8.2% | −13.3% | −43.7% | −61.7% | −64.4% | |
| Nov 14, 2023 | NMRA | $12 | $40.2K | +0.1% | +23.4% | +52.4% | −19.2% | −1.4% | −85.0% | |
| Nov 13, 2023 | NMRA | $12 | $371.9K | +0.8% | +19.1% | +48.2% | −25.1% | −9.9% | −85.1% | |
| Nov 10, 2023 | NMRA | $11 | $134.7K | +0.3% | +12.0% | +56.0% | −20.6% | +17.8% | −84.6% | |
| Nov 10, 2023 | NMRA | $12 | $63.8K | +0.1% | +12.0% | +56.0% | −20.6% | +17.8% | −84.6% | |
| Nov 9, 2023 | NMRA | $11 | $327.3K | +0.8% | +22.4% | +73.8% | −7.8% | +28.7% | −83.2% | |
| Nov 8, 2023 | NMRA | $11 | $745.2K | +1.7% | +18.3% | +64.2% | −11.4% | +27.4% | −83.3% | |
| Nov 8, 2023 | NMRA | $12 | $272.6K | +0.6% | +18.3% | +64.2% | −11.4% | +27.4% | −83.3% | |
| Nov 7, 2023 | NMRA | $12 | $347.2K | +0.8% | +7.6% | +46.3% | −15.4% | +12.2% | −84.7% | |
| Nov 6, 2023 | NMRA | $12 | $497.6K | +1.1% | +3.2% | +41.3% | −18.1% | +11.4% | −84.4% | |
| Nov 3, 2023 | NMRA | $11 | $255.1K | +0.6% | −0.5% | +28.1% | −21.9% | −1.2% | −85.0% | |
| Sep 29, 2023 | NMRA | $14 | $483.1K | +0.9% | −22.3% | +20.8% | −1.2% | −6.4% | −87.4% | |
| Sep 28, 2023 | NMRA | $13 | $219.9K | +0.4% | −17.0% | +29.7% | +4.0% | −0.1% | −86.5% | |
| Sep 28, 2023 | NMRA | $14 | $343.8K | +0.7% | −17.0% | +29.7% | +4.0% | −0.1% | −86.5% | |
| Sep 27, 2023 | NMRA | $12 | $301.6K | +0.7% | −1.3% | +51.4% | +6.7% | +9.3% | −84.9% | |
| Sep 26, 2023 | NMRA | $12 | $398.8K | +0.9% | +5.0% | +49.5% | +7.7% | +11.7% | −84.8% | |
| Sep 25, 2023 | NMRA | $11 | $332.3K | +0.8% | +2.4% | +53.6% | +9.1% | +12.3% | −84.4% | |
| Sep 25, 2023 | NMRA | $12 | $349.1K | +0.8% | +2.4% | +53.6% | +9.1% | +12.3% | −84.4% | |
| Sep 22, 2023 | NMRA | $11 | $445.6K | +1.1% | −11.3% | +58.7% | +19.8% | +15.9% | −83.9% | |
| Sep 19, 2023 | NMRA | $17 | $25.5M | +71% | −17.3% | +21.5% | +17.1% | +6.3% | −85.1% |
How this is calculated. We score only open-market purchases (SEC code
P) — the buys that carry real signal. Each trade's return is measured from the adjusted closing price on the purchase date to the latest close, accounting for stock splits and dividends. The 1M/3M/6M/12M columns show the same trade's return after each fixed holding period; a dash means that horizon hasn't elapsed yet or isn't priceable. Sales are excluded because insiders sell for many routine reasons. With only 23 scored trades, treat this as a small sample, not a verdict.
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Open-market buys
$126.23M
25 trades
Open-market sells
$0
0 trades
Net flow
+$126.23M
Net buying
Total filings
31
transactions shown
Full transaction history
All Form 4 activity across every company, newest firstSPTX
Arch Venture Partners Xii, Llc, SPTX's 10% owner, spent $19.8M of their own money on 1.1M shares at $18, growing their stake 21%.
+$19.8M
1.1M sh @ $18
MTSR
−$0
8.31M sh
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $5M of their own money on 1.92M shares at $3, growing their stake 46%.
+$5M
1.92M sh @ $3
PRME
Arch Venture Partners Xii, Llc, PRME's 10% owner, spent $10M of their own money on 3.03M shares at $3, growing their stake 95%.
+$10M
3.03M sh @ $3
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MTSR
+$0
7.52M sh
MTSR
Arch Venture Partners Xii, Llc, MTSR's 10% owner, spent $25.78M of their own money on 1.43M shares at $18, growing their stake 8%.
+$25.78M
1.43M sh @ $18
MTSR
Arch Venture Partners Xii, Llc, MTSR's 10% owner, spent $14.22M of their own money on 789,998 shares at $18, growing their stake 11%.
+$14.22M
789,998 sh @ $18
RAPP
+$0
3.73M sh
PRME
Arch Venture Partners Xii, Llc, PRME's 10% owner, spent $20M of their own money on 3.2M shares at $6, opening a brand-new position.
+$20M
3.2M sh @ $6
NMRA
+$0
1.18M sh
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $40.2K of their own money on 3,357 shares at $12.
+$40.2K
3,357 sh @ $12
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $371.9K of their own money on 31,653 shares at $12, growing their stake 1%.
+$371.9K
31,653 sh @ $12
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $134.7K of their own money on 11,844 shares at $11.
+$134.7K
11,844 sh @ $11
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $63.8K of their own money on 5,431 shares at $12.
+$63.8K
5,431 sh @ $12
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $327.3K of their own money on 31,079 shares at $11, growing their stake 1%.
+$327.3K
31,079 sh @ $11
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $745.2K of their own money on 69,127 shares at $11, growing their stake 2%.
+$745.2K
69,127 sh @ $11
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $272.6K of their own money on 23,124 shares at $12, growing their stake 1%.
+$272.6K
23,124 sh @ $12
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $347.2K of their own money on 30,192 shares at $12, growing their stake 1%.
+$347.2K
30,192 sh @ $12
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $497.6K of their own money on 43,082 shares at $12, growing their stake 1%.
+$497.6K
43,082 sh @ $12
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $255.1K of their own money on 22,420 shares at $11, growing their stake 1%.
+$255.1K
22,420 sh @ $11
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $483.1K of their own money on 34,560 shares at $14, growing their stake 1%.
+$483.1K
34,560 sh @ $14
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $219.9K of their own money on 16,841 shares at $13.
+$219.9K
16,841 sh @ $13
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $343.8K of their own money on 25,110 shares at $14, growing their stake 1%.
+$343.8K
25,110 sh @ $14
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $301.6K of their own money on 24,504 shares at $12, growing their stake 1%.
+$301.6K
24,504 sh @ $12
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $398.8K of their own money on 34,000 shares at $12, growing their stake 1%.
+$398.8K
34,000 sh @ $12
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $332.3K of their own money on 30,773 shares at $11, growing their stake 1%.
+$332.3K
30,773 sh @ $11
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $349.1K of their own money on 29,967 shares at $12, growing their stake 1%.
+$349.1K
29,967 sh @ $12
NMRA
Arch Venture Partners Xii, Llc, NMRA's 10% owner, spent $445.6K of their own money on 40,000 shares at $11, growing their stake 1%.
+$445.6K
40,000 sh @ $11
NMRA
+$0
2.12M sh
Frequently asked questions
How is ARCH Venture Partners XII, LLC's win rate calculated?
We take every open-market purchase (SEC code P) we can match to a stock price, then compare the split- and dividend-adjusted price on the purchase date to the most recent close. The win rate is the share of those buys currently trading above the purchase price. Sales and share grants are not scored.
Why are some buys not included in the score?
A purchase is excluded if we can't price it — for example if the ticker is missing from the filing, the company has been delisted, or the security isn't a common stock we can match to market data. Excluded counts are shown next to the scored total.
What do the 1M / 3M / 6M / 12M columns mean?
They show each purchase's return after a fixed holding period — one, three, six, and twelve months from the buy date — using split- and dividend-adjusted prices. This separates good entry timing from simply holding a long-running winner. A dash means that horizon hasn't elapsed yet for that trade, or the stock couldn't be priced at that date.
Does a high win rate mean I should copy this insider?
No. Past performance does not predict future results, sample sizes are often small, and an insider's edge in their own company doesn't transfer to yours. This is context, not a recommendation. InsiderSource is not investment advice.
Where does this data come from?
Trades come from ARCH Venture Partners XII, LLC's SEC Form 4 filings on EDGAR. Prices come from public market data and are split/dividend-adjusted. Always verify against the original filings before acting.