Short selling at the Chicago Stock Exchange

Discussion in 'Options' started by arturo100, Sep 15, 2024.

  1. NYSE Chicago, formerly known as the Chicago Stock Exchange (CHX), is one of the premier venues for option contingent stock trades (combined stock-option trades).
    https://www.nyse.com/markets/nyse-chicago

    However, I have been researching monthly stock short trade data reported by finra on all major US stock exchanges (https://www.finra.org/finra-data/br...e-volume-data/monthly-short-sale-volume-files) and I could not find any short trade that happened at the CHX. I mean, I can easily reconstruct all short trades made, say, at Nasdaq, but I cannot find any of them that happened in Chicago. Does anyone know why?
     
  2. Robert Morse

    Robert Morse Sponsor

    This file does not provide that?
    upload_2024-9-15_6-52-33.png
     
  3. Apparently not. I searched several trades happened at the CHX, as reported by IQFeed, and no one was on the file that you mention. That's bizarre.
     
  4. Robert Morse

    Robert Morse Sponsor

    May I ask, does it matter what exchange short selling occurred at? I would think end of day data of short interest offers more information, as those shares require a borrow.
     
  5. T
    Thanks Robert. Basically, I am looking at Times&Sales data provided by IQFeed. The trades labeled with a "8" in the market center column are traded at the CHX. I sampled randomly at least 50 of them and no one had a correspondent one in any of the files monthly provided by finra. Instead, as I said, I have no problem in spotting short trades happened in other US markets using this same approach.
     
  6. Databento

    Databento Sponsor

    It's because you're looking at the wrong place.

    The TRFs are where ATSes (informally called "dark pools") report their trades. The short trades you see in those files are going to be ones on venues like UBS, Instinet, LeveL ATS, Blue Ocean, JPM-X, Sigma X2, etc. Not short trades on exchanges like NYSE, NYSE Chicago, Nasdaq, etc.

    FINRA is responsible for publishing such trade data for the ORF, ADF, TRFs, and the same of corporate bonds through TRACE, and so on. But it's not responsible for publishing on-exchange trades in NMS stocks. As mandated by Reg NMS, that's public responsibility of the SIPs (and private responsibility of exchange prop feeds).

    "Nasdaq TRF Carteret" and "Nasdaq TRF Chicago" may sound confusingly similar to the Nasdaq and NYSE Chicago exchanges respectively, but they're completely different venues.

    You can get NYSE Chicago short trades from any data source that attributes them properly. For example with Databento:

    Code:
    import databento as db
    
    
    client = db.Historical()
    
    data = client.timeseries.get_range(
        dataset="DBEQ.BASIC",
        schema="trades",
        symbols="ALL_SYMBOLS",
        start="2024-09-10T13:00",
        end="2024-09-11T15:00",
    )
    
    # ALL_SYMBOLS requests do not automatically map symbols
    symbology_json = data.request_symbology(client)
    data.insert_symbology_json(symbology_json)
    
    df = data.to_df(tz="US/Eastern")
    
    # DBEQ.BASIC contains trades from multiple venues, filter for only XCHI
    # You can get full list of publishers from metadata.list_publishers endpoint
    df_chx_shorts = df[(df["publisher_id"] == 39) & (df["side"] == "A")]
    
    print(df_chx_shorts)
    Code:
                                                                   ts_event  rtype  publisher_id  instrument_id action side  depth   price  size  flags  ts_in_delta  sequence symbol
    ts_recv
    2024-09-10 09:02:59.132261015-04:00 2024-09-10 09:02:59.132028288-04:00      0            39          18811      T    A      0   19.62   200    130       205024    115765   RYDE
    2024-09-10 09:08:16.217420896-04:00 2024-09-10 09:08:16.217192030-04:00      0            39          12336      T    A      0   14.80   100    130       203995    122473    PBR
    2024-09-10 09:16:16.129348408-04:00 2024-09-10 09:16:16.129122868-04:00      0            39          18669      T    A      0   33.02    43    130       203126    129403   EZBC
    2024-09-10 09:16:16.129430151-04:00 2024-09-10 09:16:16.129215859-04:00      0            39          18669      T    A      0   33.02     6    130       203100    129404   EZBC
    2024-09-10 09:16:16.129491589-04:00 2024-09-10 09:16:16.129276390-04:00      0            39          18669      T    A      0   33.02     1    130       203024    129405   EZBC
    ...                                                                 ...    ...           ...            ...    ...  ...    ...     ...   ...    ...          ...       ...    ...
    [66760 rows x 13 columns]
     
    Last edited: Sep 15, 2024
  7. MarkBrown

    MarkBrown

    is the data from databeno streaming tick by tick? or is 1 second as low as you go?
     
  8. poopy

    poopy


    You need tick data to short dime puts?
     
  9. MarkBrown

    MarkBrown

    don't trade options myself just as you know i was the computer guru for the worlds largest option trader.

    see unlike option traders who have no clue - i trade strait up futures cause i know the direction of the market and don't have to make guesses.
     
  10. Robert Morse

    Robert Morse Sponsor

    Know I did not. And who was that?

     
    #10     Sep 15, 2024