Related subjects
/related-subjects
Returns the non-asset subjects most frequently discussed in the same posts as exactly one resolved asset or non-asset subject. Each row includes shared activity and the anchor's sentiment within that conversation. Asset selectors support equities, commodities, indices, and crypto assets returned by GET /assets; commodity and index IDs use asset_class=equity. Parameter rules: One of asset_id or subject_id is required. asset_id requires asset_class. subject_id and asset_class cannot be combined. subject_id and asset_id cannot be combined.
Parameters
Canonical identifier returned by /assets. Stock, commodity, and index IDs are normally ticker or market symbols and use asset_class=equity; crypto IDs are canonical crypto slugs. asset_class is mandatory whenever asset_id is present.
Example:NVDA
Namespace of asset_id, or the market class for endpoints with a class-scoped global view. Stocks, commodities, and indices use equity. Equity is the documented default only where the endpoint description states a default.
equitycrypto
Example:equity
Canonical non-asset identifier returned by /subjects. It cannot be combined with asset_id or asset_class.
Example:person:donald_trump
Lookback window in hours.
Default:168
Maximum results returned.
Default:25
cURL Example
curl --get \
--url 'https://nebula-api.hiddensystems.ai/api/v1/public/related-subjects' \
--data-urlencode 'asset_id=NVDA' \
--data-urlencode 'asset_class=equity' \
--header 'X-API-Key: YOUR_API_KEY'Responses
Media type application/json
authors
Distinct authors represented by the matching posts.
average_sentiment_score
Mean sentiment score across all anchor posts in the requested window.
from
Inclusive UTC start of the measured window.
hours
Lookback window represented by the response, in hours.
posts
Matching post count over the requested window.
subjects
array<object>
Non-asset subjects returned by the discovery operation.
subjects
Non-asset subjects returned by the discovery operation.
subjects[].authors
Distinct authors represented by the matching posts.
subjects[].bearish_posts
Posts classified as bearish.
subjects[].bullish_posts
Posts classified as bullish.
subjects[].first_post_at
UTC time of the first matching post in the requested window.
subjects[].last_post_at
UTC time of the latest matching post in the requested window.
subjects[].name
Human-readable name.
subjects[].neutral_posts
Posts classified as neutral.
subjects[].posts
Matching post count over the requested window.
subjects[].posts_delta
Fractional change from posts_prior to posts_recent; positive values indicate growth.
subjects[].posts_prior
Matching posts in the first half of the requested window.
subjects[].posts_recent
Matching posts in the second half of the requested window.
subjects[].sentiment_delta
Difference between sentiment_score for the shared conversation and the anchor's complete-window average.
subjects[].sentiment_score
Signed sentiment score; positive is bullish and negative is bearish.
subjects[].share
Anchor posts that also mention this subject as a decimal fraction of all anchor posts in the window.
subjects[].subject_id
Canonical identifier for a non-asset person, account, or topic.
to
Exclusive UTC end of the measured window.
{
"authors": 241,
"average_sentiment_score": 36.2,
"from": "2026-08-15T09:00:00Z",
"hours": 168,
"posts": 684,
"subjects": [
{
"authors": 73,
"bearish_posts": 41,
"bullish_posts": 112,
"first_post_at": "2026-08-15T09:00:00Z",
"last_post_at": "2026-08-22T08:45:00Z",
"name": "Artificial Intelligence",
"neutral_posts": 31,
"posts": 184,
"posts_delta": 0.515,
"posts_prior": 272,
"posts_recent": 412,
"sentiment_delta": 8.4,
"sentiment_score": 42.6,
"share": 0.148,
"subject_id": "text:artificial intelligence"
}
],
"to": "2026-08-22T09:00:00Z"
}