BlackRock’s iShares Core MSCI Emerging Markets ETF (IEMG) and Vanguard’s FTSE Emerging Markets ETF (VWO) have quietly become very different investment products.
For more than a decade, investors treated these two funds as nearly interchangeable, but a long-running index classification dispute has produced a record performance gap.
The divergence comes down to one country: South Korea, and how two major index providers have chosen to categorize its stock market.
MSCI classifies South Korea as an emerging market, while FTSE reclassified it as a developed market back in 2009, creating a fundamental structural difference between the two funds.
VWO tracks the FTSE index and carries zero exposure to South Korean equities, while IEMG tracks MSCI and holds a weighting of more than 12% in Korean names.
Samsung Electronics and SK Hynix sit near the top of IEMG’s portfolio as the second and third largest positions, while not a single South Korean company appears in VWO’s top ten holdings.
That distinction matters enormously because South Korea became one of the biggest beneficiaries of the global AI spending boom, with chipmakers tied to artificial intelligence infrastructure driving outsized returns.
Samsung and SK Hynix are dominant players in global memory chip production, and surging demand for that memory, largely driven by AI infrastructure buildouts, has been a defining investment theme of 2025 and 2026.
IEMG delivered a 33% return over the past year, comfortably ahead of VWO’s 20% gain, a gap that reflects just how much South Korean chip exposure has mattered to performance.
Bloomberg data shows IEMG attracted $22 billion in new investor money over the last 12 months, more than double VWO’s inflows over the same period.
The iShares fund now manages a record $160 billion in assets under management, while the Vanguard fund has climbed to a record $120 billion, with both portfolios expanding rapidly.
On June 23, 2026, MSCI completed its annual market classification review and confirmed South Korea would remain in the emerging markets category with no watchlist placement or formal reclassification process initiated.
MSCI CEO Henry Fernandez pointed to foreign-exchange accessibility as the central barrier, specifically the absence of a fully deliverable offshore won market that institutional investors require.
Without that offshore currency market, large institutions cannot efficiently manage currency exposure in the way a developed market designation would typically demand, Fernandez noted.
More recently, South Korea’s KOSPI Index has dropped more than 10% over the past month, erasing much of IEMG’s earlier advantage and narrowing the performance gap between the two funds.
During that same period, VWO gained 1.6% compared with just 1.1% for IEMG, illustrating how quickly the classification advantage can reverse when Korean equities sell off.
The broader lesson for investors is that adding an international or emerging markets fund to a portfolio no longer guarantees diversification without a careful look at what is inside the fund itself.
Two funds sharing the same label and general mandate can carry dramatically different country exposures, sector concentrations, and ultimately, very different risk and return profiles.
