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Companies & Events

Major Event Taxonomy

Name: Major Event Taxonomy
Creator: TW Market Data
License: https://twmarketdata.com/en/legal/licensing

MOPS (material announcements) classified into an event taxonomy (,, …) with the announcement subject, date/time, a rule version, and a classification confidence score. Not a forecast, not a recommendation.

← Major Event Taxonomy overview

ReferenceSource: MOPS·Plan: pro·Cost: 2 credits·GET /v2/datasets/major-event-taxonomy

Major Event Taxonomy is a Taiwan market dataset sourced from MOPS, served by TW Market Data as GET /v2/datasets/major-event-taxonomy, with data as of 2026-07-18.

Data as of 2026-07-18 (event_date).

Overview

Field	Type	Description
`ticker`	string
`market`	string
`event_date`	string
`event_time`	string
`subject`	string	verbatim subject
`event_class`	string	////…
`confidence`	string	classifier confidence (type, not impact)
`rule_version`	string	mops_taxonomy_v1

Coverage

Window	1993-01-05 – 2026-09-04
Grade	Reference
Measured	2026-09-04from the dataset registry

Example response

A real response from this endpoint. Rows are returned under "data", and provenance is carried in the shape shown below — it is not identical across datasets, so read this page's rather than assuming another's.

{
  "dataset_id": "major_event_taxonomy",
  "request_context": {
    "scope": "mops_material_information_classified",
    "coverage_type": "event_driven_derived",
    "filters": {
      "ticker": null,
      "market": null,
      "event_class": null,
      "event_date": null,
      "date_from": null,
      "date_to": null,
      "min_confidence": null,
      "limit": 50
    },
    "min_event_date": "2026-08-05",
    "max_event_date": "2026-08-05"
  },
  "quality": {
    "row_count": 50,
    "ticker_count": 30,
    "event_classes_present": [
      "<Chinese value - see the zh page>",
      "<Chinese value - see the zh page>",
      "<Chinese value - see the zh page>"
    ],
    "min_confidence_in_page": 0.3,
    "sensitive_fields_exposed": false
  },
  "lineage": {
    "rule_versions": [
      "mops_taxonomy_v1"
    ],
    "semantics": "MOPS material-information filings assigned an event_class by a rule engine, with the engine's confidence. The classification is DERIVED; the filing's own headline is kept in `subject` so any row can be re-judged."
  },
  "error": null,
  "data": [
    {
      "ticker": "7835",
      "market": "TW",
      "event_date": "2026-08-05",
      "event_time": "23:14:05",
      "subject": "<Chinese value - see the zh page>",
      "event_class": "<Chinese value - see the zh page>",
      "confidence": 0.6,
      "rule_version": "mops_taxonomy_v1"
    },
    {
      "ticker": "4728",
      "market": "TW",
      "event_date": "2026-08-05",
      "event_time": "22:49:04",
      "subject": "<Chinese value - see the zh page>",
      "event_class": "<Chinese value - see the zh page>",
      "confidence": 0.6,
      "rule_version": "mops_taxonomy_v1"
    }
  ],
  "data_count": 50,
  "known_gaps": [
    "event_class_is_INFERRED_by_a_rule_engine_not_an_official_field",
    "confidence_is_the_rule_engines_own_score_not_a_calibrated_probability",
    "rule_version_pins_the_classifier_that_produced_each_row"
  ],
  "warnings": [
    "not_investment_advice"
  ],
  "envelope": {
    "dataset_id": "major_event_taxonomy",
    "scope": "mops_material_information_classified",
    "row_count": 50
  }
}

Captured from the live API on 2026-07-20.

Chinese data values are shown as a marker here so this page stays in English; the /zh page shows them verbatim.

Licence and attribution

Part of the data in this service is obtained from the Government Open Data Platform (data.gov.tw) and used under the Open Government Data License, version 1.0. Providing agencies: Taiwan Stock Exchange, Taipei Exchange, Taiwan Futures Exchange, Taiwan Depository & Clearing Corporation, National Development Council, Central Bank of the Republic of China (Taiwan), Department of Statistics of the Ministry of Economic Affairs, and Customs Administration of the Ministry of Finance. The value-added processing, derived calculations and presentation in this service are the responsibility of TWMD and are not associated with the providing agencies.

Cite this dataset

TW Market Data. (2026). Major Event Taxonomy (Version 2026-07-18) [Data set]. TW Market Data. Retrieved 2026-09-05, from https://twmarketdata.com/en/docs/api/companies-events/major-event-taxonomy

The version is the dataset's own as_of, not the date this page was built. Where we have no as_of the field is left out rather than filled in. Check a signature

Datasets that join with this one. The key each pair aligns on is shown, so you can plan a multi-table query without guessing.

MOPS major events (structured)
Joins on event_date + market + ticker
Attention & disposition events
Joins on event_date + market + ticker
Capital Formation Events
Joins on event_date + market + ticker
Stock split & par-value events
Joins on event_date + market + ticker
Investor conference calendar
Joins on market + ticker

Getting started

Put your key in the X-API-Key header.
Add query parameters (symbol, date range, limit).
Send the request and read the data array.

curl "https://api.twmarketdata.com/v2/datasets/major-event-taxonomy" \
  -H "X-API-Key: sk_live_..."

Filtering

Parameter	Required	Type	Description
`symbol`	Yes	string	Ticker, e.g. 2330.
`start_date`	No	string (YYYY-MM-DD)	Start of the query range.
`end_date`	No	string (YYYY-MM-DD)	End of the query range.
`limit`	No	integer	Maximum rows to return.

Python

import requests

resp = requests.get(
    "https://api.twmarketdata.com/v2/datasets/major-event-taxonomy",
    params={},
    headers={"X-API-Key": "sk_live_..."},
)
resp.raise_for_status()
print(resp.json()["data"])

OpenAPI

This endpoint is GET /v2/datasets/major-event-taxonomy. The full machine-readable schema (parameters, security, response envelope) lives in the OpenAPI spec.

Request & Response

Request

curl "https://api.twmarketdata.com/v2/datasets/major-event-taxonomy?symbol=2330&start_date=2026-01-01&end_date=2026-06-30&limit=5" \
  -H "X-API-Key: $TWMD_API_KEY"

Response

{
  "dataset_id": "major_event_taxonomy",
  "quality": {
    "row_count": "<number>",
    "ticker_count": "<number>",
    "event_classes_present": "<array>",
    "min_confidence_in_page": "<number>",
    "sensitive_fields_exposed": "<boolean>"
  },
  "error": null,
  "data": [
    {
      "ticker": "<string>",
      "market": "<string>",
      "event_date": "<string>",
      "event_time": "<string>",
      "subject": "<string>",
      "event_class": "<string>",
      "confidence": "<number>",
      "rule_version": "<string>"
    }
  ],
  "data_count": 50,
  "known_gaps": [
    "<string>"
  ],
  "warnings": [
    "<string>"
  ],
  "envelope": {
    "dataset_id": "<string>",
    "scope": "<string>",
    "row_count": "<number>"
  }
}