BSE has announced the release of BOLT Pro TWS version 12.60, which will go live on Monday, April 20, 2026. This is an optional upgrade applicable across Equity, Equity Derivatives, Currency Derivatives, Commodity Derivatives, and EGR segments. The release introduces one new feature: a toggle between old and new sizes in the Best Five Window.

Key Points

• BOLT Pro TWS ver. 12.60 is an optional release — trading members are not mandated to upgrade.
• The new version is applicable across Equity, Equity Derivatives, Currency Derivatives, Commodity Derivatives, and EGR segments.
• New feature introduced: Best Five Window – Facility to Switch Between Old and New Sizes.
• Version available for download from the Exchange website and via the Auto-Download Interface for leased line users.
• BSE Helpdesk contact: 022-45720400/600 & 022-69158500 | bsehelp@bseindia.com

Regulatory Changes

No regulatory changes. This is a technical software update to the BOLT Pro TWS trading terminal.

Compliance Requirements

• Optional: Trading members may choose to upgrade at their discretion.
• Members using Leased Line Connections can upgrade by selecting ver. 12.60 in the TWS Version tab of the Auto-Download Interface on startup.
• Members may also download manually from the BSE website at http://www.bseindia.com/help/ by downloading Update.zip, unzipping it, and following the instructions in How to use this files.doc.

Important Dates

Impact Assessment

Minimal market impact. This is a routine, optional software upgrade to BSE’s BOLT Pro TWS trading terminal. The single feature addition (Best Five Window size toggle) is a UI/UX enhancement with no effect on trading strategies, market structure, or compliance obligations. Trading members who do not upgrade will continue to operate normally on their existing version.