DiamondStream Partners is a venture capital firm founded in 2003 and based in Seattle, Washington. The firm invests in middle-stage aerospace, aviation, and mobility transformation companies, primarily in the US and Europe, leveraging deep operational and investing expertise to help founders scale their businesses.
Their most common stage is series-a (54% of deals). Average disclosed round size is $18.3M (across 7 rounds with reported amounts).
Portfolio
10
Fund Size
—
Top Stage
Series A
Last 12 Mo
0
Team
Portfolio Breakdown
Stage Distribution
Sector Distribution
Investment Activity
DealsAvg Round Size
Portfolio
13 investments
| Company | Round | Amount | Date |
|---|---|---|---|
 Ampaire | Series B | $19M | Jan 2026 |
 Ampaire | Series B | $19M | Jan 2026 |
 Elroy Air | Unknown | — | Jan 2025 |
| Elroy Air | Unknown | — | Oct 2024 |
 SwissDrones | Series B | $10M | Apr 2024 |
 Vapaus | Series A | — | Jan 2024 |
| WWINGTRA AG | Series B | $22M | Mar 2023 |
| GGPMS International | Series A | — | Jan 2022 |
| Elroy Air | Series A | $40M | Aug 2021 |
 GPMS | Series A | — | Feb 2021 |
| GGPMS International | Series A | — | Jan 2021 |
| VVerdeGo | Series A | $12M | — |
 Volantio | Series A | $6M | — |
Top Co-Investors
Marlinspike3 shared
Lockheed Martin Ventures3 shared
Shield Capital3 shared
Levitate Capital2 shared
Snowpoint Ventures2 shared
Alaska Star Ventures2 shared
Techstars2 shared
International Airlines Group2 shared
Gaingels2 shared
Elemental Impact2 shared
Sand Hill Angels2 shared
Hearst Ventures2 shared
Ingleside Investors2 shared
EquityPitcher Ventures2 shared
Precursor Ventures1 shared
Prosperity7 Ventures1 shared
Catapult Ventures1 shared
Massive1 shared
Forward Partners1 shared
KBW Ventures1 shared
Last updated: 20 October 2026