Possible bug with Options chains

Alpaca Market Data
1

I am running this command

curl --request GET \
     --url 'https://data.alpaca.markets/v1beta1/options/snapshots/CSGP?feed=indicative&limit=100&expiration_date_gte=2025-09-26&expiration_date_lte=2025-10-24' \
     --header 'APCA-API-KEY-ID: ***' \
     --header 'APCA-API-SECRET-KEY: ***' \
     --header 'accept: application/json'

It returns symbols that do not look correct. Notice the 251017 and the 1251017 expire dates

"snapshots": {
"CSGP251017P00045000": {},
"CSGP1251017P00001000": {},
"CSGP1251017P00007000": {},
"CSGP251017C00100000":{} ...

2

@pjsteele You asked about option contracts CSGP1251017P00001000 and CSGP1251017P00007000 with what appears to be an extra digit after the symbol. Those are correct. The digit after the symbol and before the expiration date indicates it is an “adjusted” contract. These occur if there is a corporate action after the initial option was issued. Most often this happens when a company issues a dividend or has a stock split. The pre-dividend or pre-split options would include the dividend or split share while the same option, issued after the corporate action, would not. For this reason they need to be differentiated. Typically this ‘extra number’ is a digit between 1-6. Note also that adjusted options may have deliverable quantities different from the typical 100. Each one is unique. The Options Clearing Corp (OCC) specifies all option symbols and issues updates when this occurs.

In this case, there was a merger of Matterport, Inc. (MTTR) with CoStar Group (CSGP). Original Matterport options (MTTR) were renamed CSGP1 on 2025-03-03 (see here).

One can always exercise an adjusted option but typically cannot buy or sell them.

Hope that explains it.

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