GlossaryPortfolio look-throughLook-through analysisUnderlying exposureFund of funds look-through

Look-through

Look-through means analysing a fund by its underlying holdings rather than as a single line, so a portfolio of funds can be aggregated by security, sector, country or asset class.

Definition

Look-through is the practice of treating a fund as the sum of its holdings. Instead of recording "40% Fund A, 60% Fund B", a look-through view multiplies each fund's weight in the portfolio by the weight of each security, sector or country inside that fund, then adds the results across funds. The output is the portfolio's true exposure: how much of a client's money is in one company, in US equities, in BBB-rated bonds, and so on.

Why it matters

Diversification across funds can be illusory when the funds hold the same names. Look-through reveals overlap and concentration, supports mandate and regulatory limit checks, and is explicitly required of insurers under Solvency II, who must report the underlying assets of their fund investments. Advisers use it in client reports; quants use it to build factor and risk models from fund holdings.

In the API

Everything needed for a look-through is in one response per ISIN: topHoldings (with weights and, where published, the holding's ISIN), sector, geography, assetAllocation and, for bond funds, creditQuality. Example values:

json
{
  "topHoldings": [
    { "name": "Example Inc", "weight": 4.8, "isin": "US0000000000" },
    { "name": "Sample Corp", "weight": 3.9 }
  ],
  "sector": [{ "label": "Information Technology", "weight": 24.1 }],
  "assetAllocation": [{ "label": "Equity", "weight": 99.2 }]
}

The holding ISIN above is a placeholder.

Common pitfalls

Factsheets usually list the top ten holdings only, so look-through on that basis covers a fraction of the portfolio; full holdings are available mainly for ETFs. Reference dates differ between funds, and label schemes for sectors and countries need normalising before aggregation. See the portfolio look-through use case.