Wikipedia (Index Constituents)#

finance-query = { version = "...", features = ["wikipedia"] }

Capability::INDICES' IndexConstituents operation previously needed a keyed provider (FMP or Polygon). This adapter table-scrapes "List of S&P 500 companies", keylessly, for the S&P 500's member list.

Scope#

Only MajorIndex::Sp500 is served. The Nasdaq-100 and Dow Jones Wikipedia articles list their components only inside a navbox template at the bottom of the page (ticker links grouped by sector, no headquarters/CIK/founding-year columns) — a meaningfully thinner shape not worth a bespoke parser for. Both return NotSupported on this provider; route to FMP for those two instead.

Wikipedia carries no constituent-changes history table for any index in this set either, so IndexConstituentChanges is unrouted here regardless of index — FMP is the only source for that operation.

fetch_indices_quote also reports NotSupported: Wikipedia has no price data at all, so an INDICES route that includes it should also include a quoting provider (Yahoo, the default, already covers this).

Setup#

use finance_query::{Capability, Provider, Providers};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let providers = Providers::builder()
        .route(Capability::INDICES, [Provider::Wikipedia])
        .build()
        .await?;

    let spx = providers.index("^GSPC");
    for member in spx.constituents().await?.iter().take(5) {
        println!(
            "{}: {} ({})",
            member.symbol,
            member.name.as_deref().unwrap_or("?"),
            member.sector.as_deref().unwrap_or("?")
        );
    }
    Ok(())
}

What the Fields Mean#

IndexConstituent's eight columns come straight off the Wikipedia table's eight columns, in order — symbol, company name, GICS sector, GICS sub-industry, headquarters location, date added, CIK, and founding year. See Indices for the full field table.

Rate Limits#

Wikipedia documents no formal quota for article fetches. These are static, rarely-changing pages, so the client self-paces conservatively at 1 request/second regardless.

Next Steps#

• Indices: the Index handle, .constituents(), and the full field reference
• FMP Provider: keyed alternative covering all three major indices plus constituent-change history
• Providers Overview: routing and fallback