The MetaTrader 5 platform was updated to Build 3391 yesterday. It is already available for automatic upgrade via platform's Check Desktop Updates feature. The new release adds many new features to the platform:

MetaQuotes' forum announcement thread:
https://www.mql5.com/en/forum/428699
If you find a bug or some undocumented feature in the new build, please post about it here.
- Added automatic tutorial upon the first launch of the MT5 platform.
- Fixed bulk position closing.
- Fixed display of negative historical prices.
- Optimized the terminal's resource consumption.
- Expanded the fundamental data for trading instruments.
- Fixed stop-loss and take-profit fields in the order opening interface to comply with FIFO rules.
- Introduced math functions over matrices and vectors.
- Added multiple activation and derivative methods for matrices and vectors.
- Added multiple loss functions for matrices and vectors.
- Added the
matrix::CompareByDigits
andvector::CompareByDigits
methods for matrix and vector comparison. - The
MathMin
andMathMax
functions now work on strings to compare strings letter by letter (as for sorting). - Increased the maximum number of OpenCL objects from 256 to 65536.
- OpenCL objects can now work with GPUs without the
double
support. - Fixed operation of the
CustomBookAdd
function. - Fixed operation of the
CalendarValueLast
function. - Fixed
ArrayBSearch
to return the first result if several identical elements are found. - Fixed checks for template function visibility within a class.
- Fixed MetaAssist tooltips.
- Added %terminal% macros to MQL5 to get the full path to the terminal's data folder.
- Improved display of arrays in the debugger.
- Increased buffer size for copying values from the debugger.
- Improved hints for compilation errors.
- Fixed *.mproj project file format to store paths to other files in a relative form, so the projects can now be moved without producing compilation errors.
- BMP files can now be embedded without the use of the
ResourceReadImage
function. - Improved reading of extended BMP formats.
- Fixed some other errors.

MetaQuotes' forum announcement thread:
https://www.mql5.com/en/forum/428699
If you find a bug or some undocumented feature in the new build, please post about it here.