--- title: "What is a reference portfolio?" slug: "what-is-a-reference-portfolio" tags: ["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).