Why Adjusted Prices Can Produce Non-Lot-Sized Share Quantities

Summary

The document addresses a backtest or trading-log puzzle: a buy order is calculated by rounding available cash down to a whole multiple of 100 shares, yet the recorded final purchase quantity is not a multiple of 100. The explanation given is that the system uses back-adjusted prices. When the calculation is performed using adjusted prices, the share amount may not reflect the expected lot size; using actual, unadjusted prices restores the expected multiple in the reported quantity.

The exchange is a brief troubleshooting answer and does not detail the platform’s adjustment mechanics, corporate-action treatment, or order execution behavior. It presents no broader test or examples beyond the user’s described calculation and the stated resolution. The practical lesson is to check whether price data used for sizing is adjusted, and to distinguish adjusted historical values from actual transaction prices when interpreting share quantities.

Key ideas

• The reported order quantity can differ from a 100-share multiple when sizing uses back-adjusted prices.
• The example calculates the buy amount by flooring affordable shares to a multiple of 100.
• The response says using actual prices yields quantities that are multiples of 100.
• The page does not explain the platform’s adjustment mechanics or discuss other causes of lot-size discrepancies.

Tags

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.