Options Meerkat

Case study

A stock fell hard, then came back. What did its options show along the way?

Coherent (COHR) fell 12.5% in one session, from $237.53 at the close of October 21, 2026 to $207.82 on October 22, then won back 6.6% by October 26. Every session of it left two traces in its options: how many contracts traded, and, counted overnight, how many of them stayed open. Here is one path through them in Options Meerkat, a step at a time: the move, the volume, what stayed open, where it went, what came before the fall, the price of protection, and what none of it can tell you.

The data: COHR's stored daily chains of the five sessions from October 20 to October 26, 2026, each the session's own last quotes, the open interest in each as counted at the close before, and the large prints stored from October 19. The answers the dashboard plays with each step were recorded on the morning of October 27, before October 26's open interest was counted; the dashboard around them is live, so whatever else it shows is today's data. The quotes it read were delayed about 15 minutes.

Recorded answers from the morning of October 27, 2026, played on the live dashboard.

  1. Step 1 of 7 · The move

    Mark the fall and the rebound

    “Show COHR's daily closes from Oct 20 to Oct 26, 2026: where were the high and the low, how far did it fall and how far did it come back, and how many sessions did each take?”

    Before
    $237.53 the close of Oct 21
    The low
    $207.82 Oct 22, 12.5% lower, in one session
    The rebound
    $221.50 Oct 26, 6.6% off the low
    Shares
    12.5M traded on Oct 22, twice the days around it

    The whole fall came in one session, and the stock never closed lower: the next two sessions won back $13.68 of the $29.71, about 46%. It was not COHR's alone. GE Vernova, AMD, Marvell, and Howmet fell the same session, and COHR had already come down from about $311 on October 9. The stored days around that are sparse, so this case reads the five sessions in a row the server kept, from October 20 to 26.

    Next The price says what happened. The options say how people traded it: start with how much changed hands each session.

  2. Step 2 of 7 · The volume

    Count what traded each session

    “Session by session from Oct 20 to Oct 26, 2026, how many COHR calls and puts traded, and how did the put/call volume ratio move through the fall and the rebound?”

    SessionCOHRCallsPutsPut/call
    Oct 20$231.809,2628,8270.95
    Oct 21$237.538,7578,4290.96
    Oct 22 the fall$207.8226,82554,9062.05
    Oct 23$209.2914,88613,5200.91
    Oct 26$221.5017,7909,5780.54

    Before the fall, calls and puts traded about evenly. On the day of it, put volume rose more than sixfold and the ratio went to 2.05; the next session it was back under 1, and on the rebound calls traded nearly twice the puts. The volume moved with the price, on the same day, not ahead of it. And volume counts every trade, closing ones as much as opening ones. (Options flow)

    Where the recorded answer differs Meerkat's answer has the October 30 217.5 call opening about 1,600 contracts on the rebound of October 26. Those opened on October 23, the session after the fall (step 4).

    Next A contract traded is not a contract held: a buyer may be closing what a seller opened. The next morning's open interest says which way it netted.

  3. Step 3 of 7 · What stayed open

    Read each session's open interest the morning after

    “For each COHR session from Oct 20 to Oct 26, 2026, how much call and put open interest did its trading open or close on balance? Open interest is counted overnight, so read each session's change from the next session's count, against the volume.”

    SessionPuts tradedPuts openedCalls tradedCalls opened
    Oct 208,827+2,5449,262+3,371
    Oct 218,429+3,1678,757+2,770
    Oct 22 the fall54,906+8,44526,825+11,604
    Oct 2313,520+3,82914,886+5,986
    Oct 269,578not counted yet17,790not counted yet

    Of the 54,906 puts traded on the day of the fall, only 8,445 more were open the next morning: about one in six. The rest closed positions, or were opened and closed again within the day. Calls, at half the volume, added more open interest than puts did, 11,604 contracts. The put/call ratio of step 2 read the fall as a rush into puts; what stayed open says the session was as much puts being taken off, and calls being put on. Every session added positions on both sides, the totals summed over the contracts listed in both counts, so a contract expiring in the session is left out. (Unusual options activity)

    Next A sum over the chain hides where the positions went. Find the contracts that gained and lost the most.

  4. Step 4 of 7 · Where they sat

    Find the strikes that filled and emptied

    “Which COHR contracts gained the most open interest during the fall, and which lost the most around the low and in the rebound? Show each one's strike against the stock price.”

    SessionContractStrike vs stockTradedOpen interest
    Oct 22Oct 23 260 put+25%4,164−1,183
    Oct 22Oct 23 245 put+18%1,276−732
    Oct 22Oct 23 210 call+1%1,810+1,340
    Oct 22Jun 2027 150 put−28%1,208+1,194
    Oct 22Jun 2027 160 put−23%1,155+1,127
    Oct 23Oct 30 217.5 call+5%1,608+1,600
    Oct 23Nov 20 240 put+15%531−333

    Three kinds of trade, all on the same two days. Puts far in the money, expiring the next day, were closed (or exercised) on the day of the fall: protection that had paid, taken off. New puts went on at the other end, far below the stock and eight months out, nearly every contract traded staying open. And calls were opened at the money, a 210 call expiring the next day on the fall, and on the session after it the October 30 217.5 call, 1,600 of 1,608 traded staying open, with the stock at $207.99. By October 26's close of $221.50, that call was in the money. Whoever held it, and against what, the count does not say. (The Greeks)

    Where the recorded answer differs Meerkat's answer reads the October 23 260 and 245 puts' fall in open interest as contracts expiring that Friday. It came in October 22's trading: the puts were still listed in October 23's count, a day before they expired. And it calls the long-dated puts "bought"; open interest says they were opened, not by which side.

    Next All of this came on the day of the fall and after. The question a reader asks first is whether the options said anything before it.

  5. Step 5 of 7 · Before the fall

    Look for a warning in the sessions before

    “In the five sessions before COHR's fall began on Oct 22, 2026, were there large or unusual put prints, and did the next session's open interest show they opened positions?”

    SessionPut premiumPrints of $1M or morePuts opened
    Oct 19$10.5M3, all at the bidnot stored
    Oct 20$5.2Mnone+2,544
    Oct 21$11.2M1, at the mid+3,167
    Oct 22 the fall$187M—+8,445

    Nothing in the three sessions before stood out. The largest put prints of October 19 printed at the bid, puts sold more likely than bought; the opens the next counts confirm were a few hundred contracts each, the largest the October 30 200 put on October 20, +601, and the January 2027 160 put on October 21, +558, out of about 186,000 puts open. The put premium of the day of the fall was more than sixteen times any of them. Nothing here would have stood out without knowing what came next.

    Where the recorded answer differs The stored prints begin on October 19, and the daily chains skip from October 9 to October 20, so the sessions of October 15 and 16 cannot be checked at all. Meerkat's answer says so.

    Next Volume and open interest count contracts. The price of the protection, its implied volatility, is the other half of the story.

  6. Step 6 of 7 · The price of protection

    Set the positions against the IV

    “Chart COHR's 30-day at-the-money IV from Oct 20 to Oct 26, 2026. How did the IV and the 25-delta skew move against the put open interest being opened and closed?”

    30-day IV
    81–86% through the week, highest on Oct 22
    Oct 27
    82.2% the 43.5th percentile of its year
    Skew
    4.5 points 25-delta puts over calls, Oct 27

    A 12.5% fall moved COHR's at-the-money IV by a few points. Its options were already priced for large moves, at over 80% a year before the fall, and stayed there: the protection opened on the day of the fall was not bought at a panic price, and the IV did not collapse as the stock came back. What changed through the week was the volume and the positions, more than the price of the options. (Implied against realized volatility)

    Where the recorded answer differs Meerkat's answer has puts "coming off" after the bounce, put open interest going from 197.9k on October 23 to 196.1k on October 26. Most of that is the October 23 puts expiring; what October 26's trading itself opened or closed was not counted yet when it was recorded.

    Next The options have said what they can. Name what they leave unanswered.

  7. Step 7 of 7 · The edge of the data

    Name what volume and open interest cannot tell you

    “What can't COHR's option volume and open interest through this fall and rebound tell me about who traded, why, and what comes next?”

    • Who. Options clear anonymously. Open interest names no fund, dealer, or market maker.
    • Which side. Every contract opened is one bought and one sold. A long-dated put opened may be a hedge on shares, a bet on a fall, or the short leg of a spread.
    • The netting. Open interest is one number per contract a day. A position opened and closed within the session leaves no trace, and a close looks the same as an exercise.
    • The gaps. Only the days the server stored can be read; a change across a gap sums several sessions.
    • Hindsight. The low is known now. On October 22, nobody knew the close was the low.
    • Your situation. What the rest of your account holds, and how much of it you can lose.

    Where the recorded answer differs Meerkat's answer names “+1,600 in the Oct-30 200 put on Oct 20”. That put opened 601 contracts that session; the 1,600 were the October 30 217.5 call, on October 23.

  8. What it adds up to

    From a hunch to a narrower question

    You started with “Did the options market know?”

    You ended with “In COHR's fall, the options showed it as it happened, not before: put volume doubled the calls on the day, but most of it closed puts, the new positions were long-dated puts and at-the-money calls, and the rebound came on call volume twice the puts.”

    The checks, to use again

    1. Mark the move first. −12.5% in one session, 46% of it back in two.
    2. Count the volume by side. Put/call 2.05 on the day of the fall, 0.54 on the rebound.
    3. Read the open interest the morning after. One in six puts traded on the fall stayed open.
    4. Find the strikes that filled and emptied. Near puts closed, far puts opened, calls opened at the money.
    5. Look before the move, and check it the next day. The largest opens before the fall were a few hundred contracts.

    Volume says how much was traded; the next morning's open interest says how much of it stayed. Neither says who, or what happens next. What to do with that is a decision the data does not make for you.

  9. Your turn

    Ask your own questions

    The same checks work on any symbol of the S&P 500 or the Nasdaq-100, over the sessions Options Meerkat has stored. Click one to put it in Meerkat's chat, in the dashboard, then press Enter. Asking needs a free sign-in.

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