Theme Ranking

After the market closes for the day, this screen groups KOSPI and KOSDAQ stocks by theme to rank which themes saw concentrated price gains and trading value. A heatmap of the top 30 themes appears at the top (tile size shows trading value, color shows average price change), followed by the ranked list starting from 1st place. Clicking a theme expands its constituent stocks' current price, trading value, and price change, along with a link to the detailed theme page. The stock-by-stock tab at the top displays individual stocks with high price changes on that day and the reasons behind them. The Korea/US switch at the top shows a ranking of US-listed stocks grouped by Nasdaq industry classification; only the top 10 stocks by trading value are listed per industry, and unlike the US Sector Radar's medium-term strength versus the index, this shows one day's movement.

Themes collect theme tags assigned to individual stocks by this site, and a single stock can belong to multiple themes at the same time. A theme's price change is the simple average of its constituent stocks' daily price changes, and its trading value is the sum of its constituent stocks' daily trading values. The site uses a simple average instead of market cap weighting to prevent a single large-cap stock from skewing the entire theme's values. Stocks lacking price change or trading value data for that day are excluded from the calculation. Additionally, themes whose combined trading value falls into the bottom 20 percent of all themes that day are excluded from the ranking to prevent low-volume rank spikes.

The combined ranking uses a weighted sum score of price change ranking and trading value ranking, where lower scores indicate higher ranks. Under normal conditions, both rankings carry equal weight (50 percent each). On days when KOSPI falls by 1.0 percent or more and KOSPI's ADR is 70 percent or lower, the system treats it as a down market and adjusts the weights to 70 percent trading value ranking and 30 percent price change ranking. When ranking price changes, it uses an adjusted value that subtracts the standard error from the average, rather than the average price change shown on screen. The standard error is calculated by dividing the standard deviation of constituent stocks' price changes by the square root of the stock count, meaning themes with fewer and more dispersed stocks undergo larger adjustments. This mechanism prevents themes with only 4 to 5 stocks from jumping to the top of the ranking due to one or two surging stocks. The average price change figure displayed on screen remains the unadjusted actual average.

You can sort by combined ranking, price gain, or trading value. Sorting by price gain uses the adjusted value mentioned above, sorting by trading value uses the combined trading value, and combined ranking sorts by the combined score. Changing the sort order updates both the themes shown in the heatmap and the list sequence. The small line on each row shows the average price change trend over the last 5 trading days. Searching for a theme name displays matching themes regardless of rank. A theme with high trading value and a high price change indicates that capital and attention concentrated there during that day, but because these are single-day values, this does not indicate future performance on the next day.

The stock-by-stock tab displays the 30 stocks with the highest price changes that day among those with theme tags. The reasons are one-line AI (Gemini) summaries created from gathering up to 5 news headlines per stock via Naver News searches. If a stock belongs to multiple themes, the system displays the theme with the highest rank that day as its primary theme. For stocks with no ranked themes, AI selects the candidate theme most relevant to the news content. You can also view past records using date navigation, the calendar, or stock name searches.

Price change, trading value, and current price come from Korea Exchange data. Updates occur daily after market close rather than in real time during trading hours. Automated updates running twice a day around 3:35 PM KST and 9:32 AM KST the next day recalculate figures based on the most recent trading day close. The date at the top of the screen indicates the reference date, and the screen explicitly notes when data is outdated.

Theme classifications rely on tags assigned by the site and involve subjectivity, so rankings change depending on stock placement. Because a single stock can belong to multiple themes, its price movement reflects repeatedly across several themes. Price changes and trading values represent single-day figures and remain volatile, while themes with few constituent stocks remain heavily influenced by one or two stocks despite adjustments. Reasons in the stock-by-stock tab summarize news headlines, which may differ from the actual causes of price movements, and reasons remain blank if no headlines are found. This screen summarizes daily market focus and does not indicate future stock prices. This is not investment advice.