---
title: "What is a reference portfolio?"
slug: "what-is-a-reference-portfolio"
updated: 2024-11-28T19:16:32Z
published: 2024-11-28T19:16:32Z
canonical: "support.lusid.com/what-is-a-reference-portfolio"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://support.lusid.com/llms.txt
> Use this file to discover all available pages before exploring further.

# What is a reference portfolio?

A *reference portfolio* enables you to model an index such as the FTSE 100 or S&P 500 in LUSID. [See how to create a reference portfolio](/v1/docs/how-do-i-create-a-reference-portfolio).

Once created, you load constituents into the reference portfolio, each of which consists of a reference to an underlying instrument and a weight, which can optionally float and be automatically rebalanced on a regular basis.

**Required reading**: [Loading constituents and rebalancing a reference portfolio](/v1/docs/loading-constituents-and-rebalancing-a-reference-portfolio).

Note the following:

- LUSID does not store [instruments](/v1/docs/instruments) themselves in a reference portfolio, but rather resolves constituents *to* instruments stored in the LUSID Security Master.
- Constituents may themselves be securitised reference portfolios, enabling you to create a blended benchmark. For more information and a worked example, see [this Jupyter Notebook](https://github.com/finbourne/finbourne-notebooks/blob/main/V1/examples/use-cases/models-and-indices/Setting%20up%20a%20blended%20benchmark%20with%20floating%20weights.ipynb).