# Stamping a Portfolio

vBase enables investors, allocators, and researchers to build a globally credible live performance record by [stamping](/overview/what-is-a-stamp.md) portfolio rebalance weights.

To ensure accurate parsing, uploads via the [Portfolio Stamping](https://app.vbase.com/stamp/?method=portfolio) interface must follow a simple standard format. To stamp a file of arbitrary structure, use the [File Stamping](https://app.vbase.com/stamp/?method=file) interface.

## What counts as a valid portfolio upload?

A portfolio must provide:

| Requirement              | Description                                          |
| ------------------------ | ---------------------------------------------------- |
| **Symbols**              | Valid tickers or identifiers                         |
| **Weights**              | Numeric values (long/short), decimals or percentages |
| **One row per security** | No multi-line entries                                |

You may paste directly into the textbox, upload a CSV file, or drag & drop a CSV into the textbox.

vBase accepts comma, semicolon, or tab delimiters, with comma as the default. Mixing different delimiters within the same file will cause an Invalid Structure error.

**Minimal Example (ready for paste)**\
symbol,weight\
AAPL,0.50\
MSFT,-0.20\
SPY,0.70

## Assigning Portfolio to a Collection

Every portfolio stamp must belong to a **Portfolio Collection**.

> 📌 A Collection organizes portfolio stamps into a verifiable investment strategy or signal.

You can add new collections by clicking the + icon next to the collection dropdown or [in your account](https://app.vbase.com/profile/#collections)

## Optional column headers

Headers are not required — but if included, they must **map to known names**.

**Valid symbol column names** id,symbol,identifier,sym,symbol,ticker,ticker\_symbol,security,asset,instrument,stock ticker,figi,isin,bbgid,bbg\_ticker,bloomberg\_id

**Valid weight column names** wt,w,weight,weight\_pct,weight\_percent,weighting,percentage,pct,allocation,exposure,position,% of book,portfolio\_weight,allocation\_pct,allocation\_percent

> If headers are missing, vBase assumes: **Column 1 = Symbol**, **Column 2 = Weight**

## Weight parsing rules

*We standardize all values before stamping*

vBase normalizes:

| Input   | Normalized Result |
| ------- | ----------------: |
| `0.25`  |              0.25 |
| `.25`   |              0.25 |
| `0,25`  |              0.25 |
| `25%`   |              0.25 |
| `-2.5%` |            -0.025 |
| `(25%)` |             -0.25 |

> ⚠️ If both comma **and** dot decimals are used to designate decimals, this is is ambiguous and the upload will be rejected

## Portfolio Normalization

Before stamping, vBase automatically:

* Strips spaces, parentheses, thousands separators
* Converts percentages → decimals
* Converts European decimal formatting to US style
* Sums weights of duplicate tickers
* Validates structure & data types

📌 Only a fingerprint of the **Normalized CSV** is stamped — not the original.

## Storage

You can download the normalized CSV file on the confirmation page, or anytime via your account's [Stamped File Storage](https://app.vbase.com/profile/#user_data_storage).

Any copy of these stamped, normalized CSV files [verifies your portfolio track record](/overview/what-vbase-verifies.md) by showing that your history of rebalances is timestamped, complete and impartially presented.


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