KABAKOFF DAVID S
CIK 1024008 · View on SEC EDGAR ↗
Insider
First SEC filing: July 24, 2019 · Latest: July 24, 2019
On this page
Insider at
Insider transactions
0 buys (P)
0 sells (S)
Net:
$0
+ 15 non-open-market transactions below
last 12 months, based on the transactions shown below
Price change vs current quote, split-adjusted for corporate actions since the filing — not benchmarked, not annualized, not size-weighted
15 other filings hidden
| Date | Ticker | Code | Shares | Price | Value | Owned after | Δ own | A/D | vs now |
|---|---|---|---|---|---|---|---|---|---|
| July 29, 2019 | CSTL | P | 62,500 | $16.00 | $1,000,000 | 1,833,577 Indirect | +3.53% | Acquired | 88.9% (price as of 2026-08-19) |
| July 29, 2019 | CSTL | S | 9 | $16.00 | $144 | 1,771,077 Indirect | 0.00% | Disposed | 88.9% (price as of 2026-08-19) |
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 (3,510) | $2.02 | June 17, 2036 | 3,510 | Acquired |
| June 20, 2025 | NXTC | Stock Option (Right to Buy) | Common Stock (28,050) | $0.47 | June 19, 2035 | 28,050 | Acquired |
| June 20, 2024 | NXTC | Stock Option (Right to Buy) | Common Stock (28,050) | $1.50 | June 19, 2034 | 28,050 | Acquired |
| June 22, 2023 | NXTC | Stock Option (Right to Buy) | Common Stock (14,250) | $1.62 | June 21, 2033 | 14,250 | Acquired |
| June 11, 2020 | NXTC | Stock Option (Right to Buy) | Common Stock (14,250) | $24.13 | June 10, 2030 | 14,250 | Acquired |
| July 29, 2019 | CSTL | Warrant to purchase Series F Preferred Stock | Common Stock (11,572) | $0.02 | July 29, 2019 | 14,107 | Disposed |
| July 29, 2019 | CSTL | Convertible Promissory Note | Common Stock (83,453) | — | — | — | Disposed |
| July 29, 2019 | CSTL | Series F Preferred Stock | Common Stock (982,785) | — | — | 1,198,016 | Disposed |
| July 29, 2019 | CSTL | Series E-3 Preferred Stock | Common Stock (318,842) | — | — | 388,669 | Disposed |
| July 29, 2019 | CSTL | Series E-2 Preferred Stock | Common Stock (358,416) | — | — | 436,910 | Disposed |
| July 29, 2019 | CSTL | Series A Preferred Stock | Common Stock (16,015) | — | — | 19,524 | Disposed |
| June 13, 2019 | NXTC | Stock Option (Right to Buy) | Common Stock (22,000) | $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)→ Common Stock (30,895) | 30,895 | Direct |
| July 24, 2019 | CSTL | Series A Preferred Stock→ Common Stock (16,015) | 16,015 | Indirect |
| July 24, 2019 | CSTL | Series E-2 Preferred Stock→ Common Stock (358,416) | 358,416 | Indirect |
| July 24, 2019 | CSTL | Series E-3 Preferred Stock→ Common Stock (318,842) | 318,842 | Indirect |
| July 24, 2019 | CSTL | Series F Preferred Stock→ Common Stock (982,785) | 982,785 | Indirect |
| July 24, 2019 | CSTL | Convertible Promissory Note→ Common Stock | — | Indirect |
| July 24, 2019 | CSTL | Warrant to purchase Series F Preferred Stock→ Series F Preferred Stock (14,107) | 14,107 | Indirect |
| May 8, 2019 | NXTC | Common Stock | 62,237 | Direct |
| May 8, 2019 | NXTC | Employee Stock Option (Right to Buy)→ Common Stock (37,342) | 37,342 | Direct |