---
title: "Strategy-tagging transactions using sub-holding keys (SHKs)"
slug: "strategy-tagging-transactions-using-sub-holding-keys-shks"
updated: 2024-08-20T13:13:10Z
published: 2024-08-20T13:13:10Z
canonical: "support.lusid.com/strategy-tagging-transactions-using-sub-holding-keys-shks"
---

> ## 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.

# Strategy-tagging transactions using sub-holding keys (SHKs)

You can tag any transaction in a transaction portfolio with a value for one or more of the [sub-holding keys](/v1/docs/what-is-a-sub-holding-key-shk) (SHKs) registered with that portfolio. Tags are retained throughout the investment lifecycle and workflow.

By default, LUSID reports holdings for a portfolio at the instrument level, so all transactions impacting an underlying instrument such as BP contribute to a calculation of your current position (quantity and cost) in a single BP holding. Consider the following set of transactions upserted to a portfolio:

| **Date** | **Instrument** | **Transaction Type** | **Quantity** |
| --- | --- | --- | --- |
| 20 May 2023 | BP | `Buy` | 100 |
| 21 May 2023 | BP | `Buy` | 150 |
| 22 May 2023 | BP | `Buy` | 50 |
| 23 May 2023 | BP | `Sell` | 50 |

When you generate a holdings report after 23 May, LUSID calculates you have a single holding of 250 BP shares.

You could instead tag the same set of transactions with distinct values for an SHK representing investment strategies, for example:

| **Date** | **Instrument** | **Transaction Type** | **Quantity** | **Strategy** |
| --- | --- | --- | --- | --- |
| 20 May 2023 | BP | `Buy` | 100 | Growth |
| 21 May 2023 | BP | `Buy` | 150 | Income |
| 22 May 2023 | BP | `Buy` | 50 | Growth |
| 23 May 2023 | BP | `Sell` | 50 | Income |

This time, LUSID calculates you have two separate BP holdings, one in a Growth strategy with 150 shares and one in an Income strategy with 100 shares. For an in-depth demonstration, work through this tutorial on [setting up a strategy-based transaction portfolio](/v1/docs/creating-a-strategy-based-transaction-portfolio).

Under-the-hood, an SHK is a *custom property*. To tag a transaction, you must first [set up the SHK](/v1/docs/what-is-a-sub-holding-key-shk#shk-setup), which means creating an underlying property type and registering it with the portfolio.

Then, you can add the SHK property and an appropriate value to a transaction:

- When you create that transaction using the `BatchUpsertTransactions` API. [See an example](/v1/docs/how-do-i-create-or-update-a-transaction#using-the-lusid-rest-api).
- Subsequently by updating transaction properties using the [UpsertTransactionProperties](https://www.lusid.com/docs/api/#operation/UpsertTransactionProperties) API, for example for `Txn-0000001`:

```json
curl -X POST 'https://<your-domain>.lusid.com/api/api/transactionportfolios/Finbourne-Examples/Global-Equity/transactions/Txn-0000001/properties'
  -H 'Content-Type: application/json-patch+json'
  -H 'Authorization: Bearer <your-API-access-token>'
  -d '{
  "Transaction/SHKs/Strategy": {
    "key": "Transaction/SHKs/Strategy",
    "value": {
      "labelValue": "Growth"
    }
  }
}'
```

> **Note**: Do *not* use `BatchUpsertTransactions` to update an existing transaction's properties, since any properties omitted from the API request are deleted rather than augmented.