ARDSLEY ADVISORY PARTNERS LP
13F filer · CIK 900529 · Norwalk, CT
Summary
ARDSLEY ADVISORY PARTNERS LP reported $960.21M across 145 positions in its 13F for 2026 Q2, filed Jul 13, 2026. The largest holdings are SNDK (5.9%), AMD (5.6%), SEZL (3.8%). Versus 2026 Q1, leaving options aside, it opened 58 new positions, added to 28, trimmed 31 and sold out of 45.
Reported value$960.21M
Positions145incl. options
Report period2026 Q2
FiledJul 13, 2026
New positions58
Added28
Trimmed31
Sold out45
Top 25 holdings
By reported value, options listed separately · change vs 2026 Q1
Weight 5.9%Value $56.69MPrice $1730Shares 25K -40.48%Since Jun 30 -23.72%
Weight 5.6%Value $54.02MPrice $607.57Shares 93K +1062.50%Since Jun 30 +4.59%
Weight 3.8%Value $36.90MPrice $107.97Shares 215K -28.33%Since Jun 30 -37.09%
Weight 2.5%Value $23.69MPrice $15.09Shares 966K -8.00%Since Jun 30 -38.46%
Weight 2.4%Value $22.67MPrice $55.69Shares 325K -7.14%Since Jun 30 -20.15%
Weight 2.3%Value $22.26MPrice $105.21Shares 201K +43.06%Since Jun 30 -5.01%
Weight 2.2%Value $21.41MPrice $7.72Shares 1.60M +40.97%Since Jun 30 -42.30%
Weight 1.9%Value $18.62MPrice $41.82Shares 390K -2.50%Since Jun 30 -12.42%
Weight 1.9%Value $18.30MPrice $130.05Shares 233KSince Jun 30 +65.56%
Weight 1.7%Value $16.62MPrice $293.67Shares 47K +161.11%Since Jun 30 -16.97%
Weight 1.7%Value $16.48MPrice $7.77Shares 1.67M -26.33%Since Jun 30 -21.52%
Weight 1.7%Value $16.45MPrice $246.67Shares 69K -34.91%Since Jun 30 +3.50%
Weight 1.7%Value $16.25MPrice $481.47Shares 30K -40.00%Since Jun 30 -11.14%
Weight 1.6%Value $15.75MPrice $39.81Shares 465K -16.22%Since Jun 30 +17.50%
Weight 1.6%Value $15.35MPrice $337.32Shares 44K +45.00%Since Jun 30 -4.39%
Weight 1.5%Value $14.64MPrice $388.41Shares 43KSince Jun 30 +14.10%
Weight 1.5%Value $14.24MPrice $290.78Shares 69K +46.19%Since Jun 30 +40.93%
Weight 1.4%Value $13.38MPrice $74.28Shares 135KSince Jun 30 -25.08%
Weight 1.4%Value $13.01MPrice $329.40Shares 45KSince Jun 30 +13.98%
Weight 1.3%Value $12.51MPrice $88.36Shares 145K +74.70%Since Jun 30 +2.37%
Weight 1.3%Value $12.02MPrice $183.72Shares 45K -50.60%Since Jun 30 -31.20%
Weight 1.2%Value $11.92MPrice $304.69Shares 32KSince Jun 30 -19.49%
Weight 1.2%Value $11.63MPrice $258.19Shares 44KSince Jun 30 -3.42%
Weight 1.1%Value $10.78MPrice $31.83Shares 220K +158.82%Since Jun 30 -35.05%
Weight 1.1%Value $10.58MPrice $77.03Shares 90KSince Jun 30 -34.50%
| Stock | Weight | Value | Since Jun 30 | Shares change | Action |
|---|---|---|---|---|---|
| 5.9% | $56.69M | -23.72% | -40.48% | Trim | |
| 5.6% | $54.02M | +4.59% | +1062.50% | Add | |
| 3.8% | $36.90M | -37.09% | -28.33% | Trim | |
| 2.5% | $23.69M | -38.46% | -8.00% | Trim | |
| 2.4% | $22.67M | -20.15% | -7.14% | Trim | |
| 2.3% | $22.26M | -5.01% | +43.06% | Add | |
| 2.2% | $21.41M | -42.30% | +40.97% | Add | |
| 1.9% | $18.62M | -12.42% | -2.50% | Trim | |
| 1.9% | $18.30M | +65.56% | — | New | |
| 1.7% | $16.62M | -16.97% | +161.11% | Add | |
| 1.7% | $16.48M | -21.52% | -26.33% | Trim | |
| 1.7% | $16.45M | +3.50% | -34.91% | Trim | |
| 1.7% | $16.25M | -11.14% | -40.00% | Trim | |
| 1.6% | $15.75M | +17.50% | -16.22% | Trim | |
| 1.6% | $15.35M | -4.39% | +45.00% | Add | |
| 1.5% | $14.64M | +14.10% | — | New | |
| 1.5% | $14.24M | +40.93% | +46.19% | Add | |
| 1.4% | $13.38M | -25.08% | — | New | |
| 1.4% | $13.01M | +13.98% | — | New | |
| 1.3% | $12.51M | +2.37% | +74.70% | Add | |
| 1.3% | $12.02M | -31.20% | -50.60% | Trim | |
| 1.2% | $11.92M | -19.49% | — | New | |
| 1.2% | $11.63M | -3.42% | — | New | |
| 1.1% | $10.78M | -35.05% | +158.82% | Add | |
| 1.1% | $10.58M | -34.50% | — | New |
Weight is the share of the reported 13F value, including options at notional value. “Since Jun 30” compares the latest close with the quarter-end price implied by the filing (value ÷ shares).
Largest buys in 2026 Q2
Largest sells in 2026 Q2
Options
Notional value, listed apart from stocks · top 10 of 15
Source: SEC Form 13F, values as reported by the filer. Filings lag up to 45 days after quarter end and cover only certain long positions. Research only, not investment advice.