Not such a hot topic as it once was, but 1Y returns as of today (June 2018) suggest BRICs may be back in fashion.
Developed markets are well past their 2008 peaks, general EM recovered somewhere mid 2017 and BRIC has only just got there.
Here’s an MSCI chart:
https://www.msci.com/documents/10199/3653ff70-93d4-4e88-9c4e-70d8efb10923
The question is - do BRICs belong in a mustachian portfolio or is it enough having them as small proportion of global ETFs? They sure look to add a lot of volatility.