Taiwan day-trading activity — a measure of activity, not of direction
The standard misreading of an activity page is to read high turnover as “the market is going up”. This page deliberately refuses to read a sign off an unsigned quantity. Activity measures how much trading happened, not which way — the same elevated day-trade share shows up in sharp rallies and in sharp declines, because activity carries no sign. On naming: the URL slug here is market-heat while the data is day-trading activity; they are the same statistic, and no separate market-heat dataset exists on this site. Day-trade share is also rule-dependent: which securities are eligible and which are under disposition measures directly change both numerator and denominator. This is market-level data and not a per-stock instruction.
What the fields are, and the aggregation basis
Rows return market-level day-trade value and share, the number of securities included, related turnover statistics, the aggregation basis and the date. The basis states which boards and trade categories are included and how the denominator is defined — change the basis and the share changes.
On no-data days and rule-change days we mark the gap rather than fill it. Carrying yesterday's figure forward manufactures a smoother curve than reality, and the break itself is information worth seeing.
Activity is not direction
More day-trade volume says only that more positions were opened and closed within the day. It does not say whether buyers or sellers were more urgent, because every trade has both sides. Treating activity as directional conviction adds a sign to a quantity that has none.
So we convert activity into no directional signal. Sentences such as "high activity means prices will rise" or "a high day-trade share means the market is bullish" will never appear here, because activity statistics cannot support them.
Rules create breaks in the series
Changes to day-trade eligibility, disposition measures such as periodic call auctions or advance payment requirements, and other trading-rule changes directly alter both the feasibility and the cost of intraday trading. When they occur, the two halves of the series are not the same thing.
Confirm that the rules were the same before comparing across periods. We keep the basis field alongside the date so you can tell whether a change came from behaviour or from regulation.
What this page must not be used for
No ranking, no screening, no price targets, no entry or exit timing and no inference about market direction. This is a market-level aggregate and not a per-stock dataset — rising market-wide activity says nothing about the trading structure of one name you hold.
The right use is as a starting question: why did activity change over this window, did the rules move, is the basis consistent, and what did prices do over the same period? Activity describes quantity; price questions need price data.