GNTX · Gentex Corp

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$23.73 -0.39 (-1.62%)

Market Cap

$5.08B

210.68M

Options Chain

15-min delayed Underlying $23.73 · today Options Calculator

Positioning

Aug 21, 2026 · 15 days to expiry · 20 contracts

Put / call OI

0.87

Balanced positioning

Open interest

811

contracts outstanding

Volume

156

traded today

Max pain

$25.00

$1.27 above spot

ATM implied vol

42.3%

market's expected move

Open interest by strike

Calls Puts

17.5

22.5

27.5

32.5

37.5

Chain

Click any strike for greeks, breakeven and the calculator

Expiry

Aug 21 15d Sep 18 43d Dec 18 134d Mar 19 225d

Calls						Puts
OI	Vol	IV	Δ	Last	Strike	Last	Δ	IV	Vol	OI
0	2	207.1%	0.904	$10.84		$0.05	—	—	2	2
Call · $15 In the money Last $10.84 Breakeven $25.84 Implied vol 207.1% Delta 0.904 ≈90% ITM Gamma 0.017 Theta -0.057 Vega 0.01 Open interest 0 Model this call Put · $15 Last $0.05 Breakeven $14.95 Implied vol — Delta — Gamma — Theta — Vega — Open interest 2 Model this put
0	—	151%	0.872	—		$0.05	—	—	40	44
Call · $17.5 In the money Last — Breakeven — Implied vol 151% Delta 0.872 ≈87% ITM Gamma 0.029 Theta -0.05 Vega 0.011 Open interest 0 Model this call Put · $17.5 Last $0.05 Breakeven $17.45 Implied vol — Delta — Gamma — Theta — Vega — Open interest 44 Model this put
3	2	107.1%	0.814	$2.65		$0.05	-0.06	56.8%	10	22
Call · $20 In the money Last $2.65 Breakeven $22.65 Implied vol 107.1% Delta 0.814 ≈81% ITM Gamma 0.052 Theta -0.047 Vega 0.012 Open interest 3 Model this call Put · $20 Last $0.05 Breakeven $19.95 Implied vol 56.8% Delta -0.06 ≈6% ITM Gamma 0.044 Theta -0.011 Vega 0.006 Open interest 22 Model this put
75	64	53%	0.705	$1.75		$0.15	-0.198	31.6%	4	132
Call · $22.5 In the money Last $1.75 Breakeven $24.25 Implied vol 53% Delta 0.705 ≈70% ITM Gamma 0.136 Theta -0.03 Vega 0.016 Open interest 75 Model this call Put · $22.5 Last $0.15 Breakeven $22.35 Implied vol 31.6% Delta -0.198 ≈20% ITM Gamma 0.184 Theta -0.014 Vega 0.012 Open interest 132 Model this put
Underlying $23.73
256	23	30.9%	0.21	$0.20		$1.35	-0.814	28.2%	1	178
Call · $25 Last $0.20 Breakeven $25.20 Implied vol 30.9% Delta 0.21 ≈21% ITM Gamma 0.195 Theta -0.014 Vega 0.013 Open interest 256 Model this call Put · $25 In the money Last $1.35 Breakeven $23.65 Implied vol 28.2% Delta -0.814 ≈81% ITM Gamma 0.201 Theta -0.011 Vega 0.013 Open interest 178 Model this put
93	2	60.1%	0.126	$0.11		—	—	—	—	0
Call · $27.5 Last $0.11 Breakeven $27.61 Implied vol 60.1% Delta 0.126 ≈13% ITM Gamma 0.071 Theta -0.02 Vega 0.009 Open interest 93 Model this call Put · $27.5 In the money Last — Breakeven — Implied vol — Delta — Gamma — Theta — Vega — Open interest 0 Model this put
5	5	83.5%	0.097	$0.05		—	—	—	—	0
Call · $30 Last $0.05 Breakeven $30.05 Implied vol 83.5% Delta 0.097 ≈10% ITM Gamma 0.042 Theta -0.023 Vega 0.01 Open interest 5 Model this call Put · $30 In the money Last — Breakeven — Implied vol — Delta — Gamma — Theta — Vega — Open interest 0 Model this put
0	—	—	—	—		—	—	—	—	0
Call · $32.5 Last — Breakeven — Implied vol — Delta — Gamma — Theta — Vega — Open interest 0 Model this call Put · $32.5 In the money Last — Breakeven — Implied vol — Delta — Gamma — Theta — Vega — Open interest 0 Model this put
1	1	—	—	$0.01		—	—	—	—	0
Call · $35 Last $0.01 Breakeven $35.01 Implied vol — Delta — Gamma — Theta — Vega — Open interest 1 Model this call Put · $35 In the money Last — Breakeven — Implied vol — Delta — Gamma — Theta — Vega — Open interest 0 Model this put
0	—	—	—	—		—	—	—	—	0
Call · $37.5 Last — Breakeven — Implied vol — Delta — Gamma — Theta — Vega — Open interest 0 Model this call Put · $37.5 In the money Last — Breakeven — Implied vol — Delta — Gamma — Theta — Vega — Open interest 0 Model this put

About this data

Greeks, implied volatility, open interest and the last price come from the latest daily snapshot and are 15-minute delayed. Bid and ask are not included on this plan.

In-the-money strikes are tinted, deepening toward the money, and the bar beside each open-interest figure scales to the heaviest strike shown. Max pain is the listed strike where the most open interest would expire worthless — a positioning reference, not a forecast.

Key facts CIK 355811 CUSIP 371901109 13F (30d) 209 filings 207 filers Visit website Investor relations