# Release Notes - Version 0.27.0¶

🚀 Welcome to hummingbot version 0.27.0! This release contains a number of new features for advanced users, along with many core stability improvements and bug fixes to the Hummingbot client.

We're also starting to see more external contributions from the Hummingbot community. See Community for more information on how to contribute to Hummingbot.

## 🔄 Order Refresh Tolerance¶

In #1673, we introduce a new parameter in the Pure Market Making (PMM) strategy: order_tolerance_refresh_pct. This allows you to set an tolerance level for refreshing orders, so that the bot only cancels and replaces orders if the market price has moved by more than a certain threshold.

This feature should help users create more custom bots and manage exchange rate limits better. See Order Refresh Tolerance for more information.

## 📊 Price Band¶

In #1713, we introduce two new parameters in the Pure Market Making (PMM) strategy: price_ceiling and price_floor. These parameters allow you set a price band within which your bot acts normally, but the bot behaves differently if the market price moves out of the band.

This feature should help users express a view that the market will stay range-bound. See Price Band for more information.

We want to thank 🙏 community member petrioptrv for this contribution!

## 🐞Fixed Memory Leak Bug¶

We fixed a critical bug #1683 that caused the bot to leak memory after users run the stop command. This caused the bot to crash unexpectedly after running for a while. This issue is now fixed.

## 🐙 Kraken Bug Fixes¶

The Kraken exchange connector, which we released in v0.26.0, had a number of bugs. In this release, we have fixed a number of Kraken related bugs, including #1664, #1671, #1676, #1696, and #1693.

This connector should be much more stable going forward.

## ⏱ LIMIT_MAKER order type in Binance¶

To fix #1633, we now use the LIMIT_MAKER order type by default for maker orders on Binance. This order type prevents your bot from making crossed orders that would be taken automatically. This feature should help users set tight spreads more effectively.

## 🐞 External DB Support¶

After #1596, you can hook up the Hummingbot client to external SQL databases. See External Database for more information.

We want to thank 🙏 community member fengkiej for this contribution!

## 🐞 Other Enhancements and Fixes¶

• Fixed a bug in which buy and sell order refreshes could sometimes get out of sync #1446
• Fixed a bug that prevented the XEMM strategy from starting #1657
• Fixed a bug that prevented the status command from execution in paper trading mode #1666
• Fixed a bug where paper trading mode didn't work on Binance due to the new LIMIT_MAKER order type #1762
• Fixed a bug with the Inventory Skew feature where orders sometimes alternate every cycle #1747
• Fixed a bug missing spreads in status in the XEMM strategy #1737
• Fixed a bug where the version number was missing from the splash screen #1739
• Fixed a bug in the Bittrex connector related to minimum order amount #1636
• Fixed a bug where the version number was missing from the splash screen #1739
• Removed deprecated deposit and withdrawal functions from the Binance connector #1731
• Removed incorrect trading pair fetcher code from the Bittrex connector #1700. We want to thank 🙏 community member aktary for this contribution!
• Fixed bugs related to input validation of the import command #1704
• Fixed a bug with incorrect display of bot duration in history command #1686