KABAKOFF DAVID S
Insider
First SEC filing: July 24, 2019 · Latest: July 24, 2019
Insider at
Insider transactions
0 buys (P)
0 sells (S)
Net: $0
Price change vs current quote, split-adjusted for corporate actions since the filing — not benchmarked, not annualized, not size-weighted
| Date | Ticker | Code | Shares | Price | Value | Owned after | Δ own | A/D | vs now |
|---|---|---|---|---|---|---|---|---|---|
| June 18, 2026 | NXTC | A | 3,510 | · | · | 3,510 Direct | · | Acquired | (price as of 2026-10-02) |
| June 20, 2025 | NXTC | A | 28,050 | · | · | 28,050 Direct | · | Acquired | (price as of 2026-10-02) |
| June 20, 2024 | NXTC | A | 28,050 | · | · | 28,050 Direct | · | Acquired | (price as of 2026-10-02) |
| June 22, 2023 | NXTC | A | 14,250 | · | · | 14,250 Direct | · | Acquired | (price as of 2026-10-02) |
| June 23, 2022 | NXTC | A | 14,250 | · | · | 14,250 Direct | · | Acquired | (price as of 2026-10-02) |
| June 24, 2021 | NXTC | A | 14,250 | · | · | 14,250 Direct | · | Acquired | (price as of 2026-10-02) |
| June 17, 2021 | CSTL | S 10b5-1 | 30,000 | $75.07 | $2,252,100 | 503,577 Indirect | -5.62% | Disposed | -52.6% (price as of 2026-10-02) |
| June 10, 2021 | CSTL | A | 3,379 | · | · | 3,379 Direct | · | Acquired | (price as of 2026-10-02) |
| June 10, 2021 | CSTL | A | 830 | · | · | 830 Direct | · | Acquired | (price as of 2026-10-02) |
| April 6, 2021 | CSTL | S 10b5-1 | 40,000 | $73.99 | $2,959,600 | 533,577 Indirect | -6.97% | Disposed | -51.9% (price as of 2026-10-02) |
| April 5, 2021 | CSTL | S 10b5-1 | 50,000 | $71.79 | $3,589,500 | 593,577 Indirect | -7.77% | Disposed | -50.5% (price as of 2026-10-02) |
| April 5, 2021 | CSTL | S 10b5-1 | 20,000 | $73.22 | $1,464,400 | 573,577 Indirect | -3.37% | Disposed | -51.4% (price as of 2026-10-02) |
| April 1, 2021 | CSTL | S 10b5-1 | 40,000 | $70.00 | $2,800,000 | 663,577 Indirect | -5.69% | Disposed | -49.2% (price as of 2026-10-02) |
| April 1, 2021 | CSTL | S 10b5-1 | 20,000 | $70.80 | $1,416,000 | 643,577 Indirect | -3.01% | Disposed | -49.8% (price as of 2026-10-02) |
| March 31, 2021 | CSTL | S 10b5-1 | 20,000 | $67.56 | $1,351,200 | 713,577 Indirect | -2.73% | Disposed | -47.4% (price as of 2026-10-02) |
| March 31, 2021 | CSTL | S 10b5-1 | 10,000 | $68.15 | $681,500 | 703,577 Indirect | -1.40% | Disposed | -47.8% (price as of 2026-10-02) |
| March 22, 2021 | CSTL | S 10b5-1 | 10,000 | $67.12 | $671,200 | 733,577 Indirect | -1.34% | Disposed | -47.0% (price as of 2026-10-02) |
| March 19, 2021 | CSTL | S 10b5-1 | 10,000 | $66.17 | $661,700 | 743,577 Indirect | -1.33% | Disposed | -46.3% (price as of 2026-10-02) |
| March 17, 2021 | CSTL | S 10b5-1 | 10,000 | $66.14 | $661,400 | 753,577 Indirect | -1.31% | Disposed | -46.2% (price as of 2026-10-02) |
| March 16, 2021 | CSTL | S 10b5-1 | 30,000 | $61.21 | $1,836,300 | 853,577 Indirect | -3.40% | Disposed | -41.9% (price as of 2026-10-02) |
| March 16, 2021 | CSTL | S 10b5-1 | 30,000 | $63.76 | $1,912,800 | 823,577 Indirect | -3.51% | Disposed | -44.2% (price as of 2026-10-02) |
| March 16, 2021 | CSTL | S 10b5-1 | 40,000 | $64.63 | $2,585,200 | 783,577 Indirect | -4.86% | Disposed | -45.0% (price as of 2026-10-02) |
| March 16, 2021 | CSTL | S 10b5-1 | 20,000 | $65.73 | $1,314,600 | 763,577 Indirect | -2.55% | Disposed | -45.9% (price as of 2026-10-02) |
| Oct. 9, 2020 | CSTL | S 10b5-1 | 25,000 | $54.16 | $1,354,000 | 883,577 Indirect | -2.75% | Disposed | -34.3% (price as of 2026-10-02) |
| Oct. 8, 2020 | CSTL | S 10b5-1 | 25,000 | $54.23 | $1,355,750 | 908,577 Indirect | -2.68% | Disposed | -34.4% (price as of 2026-10-02) |
| Oct. 6, 2020 | CSTL | S 10b5-1 | 50,000 | $53.09 | $2,654,500 | 933,577 Indirect | -5.08% | Disposed | -33.0% (price as of 2026-10-02) |
| Oct. 5, 2020 | CSTL | S 10b5-1 | 25,000 | $52.09 | $1,302,250 | 983,577 Indirect | -2.48% | Disposed | -31.7% (price as of 2026-10-02) |
| Oct. 2, 2020 | CSTL | S 10b5-1 | 25,000 | $52.07 | $1,301,750 | 1,008,577 Indirect | -2.42% | Disposed | -31.7% (price as of 2026-10-02) |
| Sept. 3, 2020 | CSTL | S 10b5-1 | 25,000 | $46.05 | $1,151,250 | 1,033,577 Indirect | -2.36% | Disposed | -22.8% (price as of 2026-10-02) |
| Aug. 19, 2020 | CSTL | S 10b5-1 | 75,000 | $44.78 | $3,358,500 | 1,058,577 Indirect | -6.62% | Disposed | -20.6% (price as of 2026-10-02) |
| Aug. 10, 2020 | CSTL | S 10b5-1 | 25,000 | $42.01 | $1,050,250 | 1,133,577 Indirect | -2.16% | Disposed | -15.4% (price as of 2026-10-02) |
| July 17, 2020 | CSTL | S 10b5-1 | 25,000 | $43.04 | $1,076,000 | 1,158,577 Indirect | -2.11% | Disposed | -17.4% (price as of 2026-10-02) |
| July 9, 2020 | CSTL | S 10b5-1 | 50,000 | $43.60 | $2,180,000 | 1,183,577 Indirect | -4.05% | Disposed | -18.4% (price as of 2026-10-02) |
| June 23, 2020 | CSTL | S 10b5-1 | 25,000 | $42.13 | $1,053,250 | 1,233,577 Indirect | -1.99% | Disposed | -15.6% (price as of 2026-10-02) |
| June 22, 2020 | CSTL | S 10b5-1 | 150,000 | $40.38 | $6,057,000 | 1,283,577 Indirect | -10.46% | Disposed | -11.9% (price as of 2026-10-02) |
| June 22, 2020 | CSTL | S 10b5-1 | 25,000 | $41.23 | $1,030,750 | 1,258,577 Indirect | -1.95% | Disposed | -13.8% (price as of 2026-10-02) |
| June 11, 2020 | NXTC | A | 14,250 | · | · | 14,250 Direct | · | Acquired | (price as of 2026-10-02) |
| June 4, 2020 | CSTL | A | 8,000 | · | · | 8,000 Direct | · | Acquired | (price as of 2026-10-02) |
| May 12, 2020 | CSTL | S 10b5-1 | 50,000 | $33.04 | $1,652,000 | 1,633,577 Indirect | -2.97% | Disposed | 7.6% (price as of 2026-10-02) |
| May 12, 2020 | CSTL | S 10b5-1 | 100,000 | $34.25 | $3,425,000 | 1,533,577 Indirect | -6.12% | Disposed | 3.8% (price as of 2026-10-02) |
| May 12, 2020 | CSTL | S 10b5-1 | 100,000 | $35.47 | $3,547,000 | 1,433,577 Indirect | -6.52% | Disposed | 0.3% (price as of 2026-10-02) |
| Feb. 19, 2020 | CSTL | S 10b5-1 | 25,000 | $32.03 | $800,750 | 1,683,577 Indirect | -1.46% | Disposed | 11.0% (price as of 2026-10-02) |
| Feb. 13, 2020 | CSTL | S 10b5-1 | 25,000 | $32.01 | $800,250 | 1,708,577 Indirect | -1.44% | Disposed | 11.1% (price as of 2026-10-02) |
| Feb. 6, 2020 | CSTL | S 10b5-1 | 25,000 | $31.03 | $775,750 | 1,733,577 Indirect | -1.42% | Disposed | 14.6% (price as of 2026-10-02) |
| Feb. 3, 2020 | CSTL | S 10b5-1 | 25,000 | $31.06 | $776,500 | 1,758,577 Indirect | -1.40% | Disposed | 14.5% (price as of 2026-10-02) |
| Jan. 31, 2020 | CSTL | S 10b5-1 | 25,000 | $30.02 | $750,500 | 1,783,577 Indirect | -1.38% | Disposed | 18.5% (price as of 2026-10-02) |
| Jan. 28, 2020 | CSTL | S 10b5-1 | 25,000 | $30.02 | $750,500 | 1,808,577 Indirect | -1.36% | Disposed | 18.5% (price as of 2026-10-02) |
| July 29, 2019 | CSTL | X | 14,107 | · | · | 0 Indirect | -100.00% | Disposed | (price as of 2026-10-02) |
| July 29, 2019 | CSTL | C | None | · | · | 0 Indirect | · | Disposed | (price as of 2026-10-02) |
| July 29, 2019 | CSTL | C | 1,198,016 | · | · | 0 Indirect | -100.00% | Disposed | (price as of 2026-10-02) |
| July 29, 2019 | CSTL | C | 388,669 | · | · | 0 Indirect | -100.00% | Disposed | (price as of 2026-10-02) |
| July 29, 2019 | CSTL | C | 436,910 | · | · | 0 Indirect | -100.00% | Disposed | (price as of 2026-10-02) |
| July 29, 2019 | CSTL | C | 19,524 | · | · | 0 Indirect | -100.00% | Disposed | (price as of 2026-10-02) |
| July 29, 2019 | CSTL | P | 62,500 | $16.00 | $1,000,000 | 1,833,577 Indirect | +3.53% | Acquired | 122.3% (price as of 2026-10-02) |
| July 29, 2019 | CSTL | S | 9 | $16.00 | $144 | 1,771,077 Indirect | 0.00% | Disposed | 122.3% (price as of 2026-10-02) |
| July 29, 2019 | CSTL | X | 11,572 | $0.02 | $231 | 1,771,086 Indirect | +0.66% | Acquired | 177700.0% (price as of 2026-10-02) |
| July 29, 2019 | CSTL | C | 83,453 | $12.80 | $1,068,198 | 1,759,514 Indirect | +4.98% | Acquired | 177.8% (price as of 2026-10-02) |
| July 29, 2019 | CSTL | C | 1,676,061 | · | · | 1,676,061 Indirect | · | Acquired | (price as of 2026-10-02) |
| June 13, 2019 | NXTC | A | 22,000 | · | · | 22,000 Direct | · | Acquired | (price as of 2026-10-02) |
P = Open-market purchase · S = Sale · A = Grant/award · M = Option exercise · G = Gift · F = Tax withholding
Insider transactions are not a recommendation; sales are often driven by liquidity or tax reasons.
Derivative holdings (Form 4 Table II) Options, RSUs and convertible securities reported on Form 4 Table II.
| Date | Ticker | Security | Underlying | Exercise price | Expiration | Shares | A/D |
|---|---|---|---|---|---|---|---|
| June 18, 2026 | NXTC | Stock Option (Right to Buy) | Common Stock | $2.02 | June 17, 2036 | 3,510 | Acquired |
| June 20, 2025 | NXTC | Stock Option (Right to Buy) | Common Stock | $0.47 | June 19, 2035 | 28,050 | Acquired |
| June 20, 2024 | NXTC | Stock Option (Right to Buy) | Common Stock | $1.50 | June 19, 2034 | 28,050 | Acquired |
| June 22, 2023 | NXTC | Stock Option (Right to Buy) | Common Stock | $1.62 | June 21, 2033 | 14,250 | Acquired |
| June 23, 2022 | NXTC | Stock Option (Right to Buy) | Common Stock | $4.77 | June 22, 2032 | 14,250 | Acquired |
| June 24, 2021 | NXTC | Stock Option (Right to Buy) | Common Stock | $8.21 | June 23, 2031 | 14,250 | Acquired |
| June 10, 2021 | CSTL | Stock option (right to buy) | Common Stock | $71.22 | June 9, 2031 | 3,379 | Acquired |
| June 10, 2021 | CSTL | Restricted Stock Units | Common Stock | · | · | 830 | Acquired |
| June 11, 2020 | NXTC | Stock Option (Right to Buy) | Common Stock | $24.13 | June 10, 2030 | 14,250 | Acquired |
| June 4, 2020 | CSTL | Stock option (right to buy) | Common Stock | $37.50 | June 3, 2030 | 8,000 | Acquired |
| July 29, 2019 | CSTL | Warrant to purchase Series F Preferred Stock | Common Stock | $0.02 | July 29, 2019 | 14,107 | Disposed |
| July 29, 2019 | CSTL | Convertible Promissory Note | Common Stock | · | · | · | Disposed |
| July 29, 2019 | CSTL | Series F Preferred Stock | Common Stock | · | · | 1,198,016 | Disposed |
| July 29, 2019 | CSTL | Series E-3 Preferred Stock | Common Stock | · | · | 388,669 | Disposed |
| July 29, 2019 | CSTL | Series E-2 Preferred Stock | Common Stock | · | · | 436,910 | Disposed |
| July 29, 2019 | CSTL | Series A Preferred Stock | Common Stock | · | · | 19,524 | Disposed |
| June 13, 2019 | NXTC | Stock Option (Right to Buy) | Common Stock | $15.57 | June 12, 2029 | 22,000 | Acquired |
Exercise/conversion price is blank when not applicable (e.g. RSUs).
Initial ownership (Form 3) 9 holdings
Securities held when first becoming an insider, per SEC Form 3.
| Date | Ticker | Security | Shares | Ownership |
|---|---|---|---|---|
| July 24, 2019 | CSTL | Stock Option (right to buy) | 30,895 | Direct |
| July 24, 2019 | CSTL | Series A Preferred Stock | 16,015 | Indirect |
| July 24, 2019 | CSTL | Series E-2 Preferred Stock | 358,416 | Indirect |
| July 24, 2019 | CSTL | Series E-3 Preferred Stock | 318,842 | Indirect |
| July 24, 2019 | CSTL | Series F Preferred Stock | 982,785 | Indirect |
| July 24, 2019 | CSTL | Convertible Promissory Note | · | Indirect |
| July 24, 2019 | CSTL | Warrant to purchase Series F Preferred Stock | 14,107 | Indirect |
| May 8, 2019 | NXTC | Common Stock | 62,237 | Direct |
| May 8, 2019 | NXTC | Employee Stock Option (Right to Buy) | 37,342 | Direct |