One of the focuses of the September market is FTSE's plan to officially upgrade the Vietnamese stock market to emerging markets on September 21. This event is of long-term significance to the position of the Vietnamese stock market, but in the short term, technical fluctuations may appear due to the mismatch between cash flows in and out.
SSI Securities Joint Stock Company estimates that the trading of ETF funds in the week from September 14-18, 2026, the week before the market officially upgraded, was worth 240 million USD with a portfolio of 27 net bought stocks.
The first disbursement of FTSE global index simulation funds is expected to take place on September 18, 2026, before the new index takes effect on September 21, 2026. Because September 18 is also the time when large foreign ETF funds have invested in the Vietnamese market such as Xtrackers, VanEck, Fubon to restructure their portfolios, the buying/selling value of each stock will be affected simultaneously by the addition/removal and restructuring activities of all funds.
Notably, VIC shares, although this code was strongly bought by Vanguard funds, were net sold by the remaining ETFs, especially due to the restructuring of Xtrackers (implementing to reduce the proportion from 31.6% to 15%).
MBS Securities Company (CTCK) assessed that, according to the "Selling once, buying many installments" mechanism, ETF funds simulating the Frontier Markets index are forced to pay off and net sell the entire Vietnamese stock portfolio once before September 21. Meanwhile, Emerging Markets funds only disburse the first installment with a modest proportion of about 10% (in 2026), the next installments (3 installments) will take place in 2027.
The difference in disbursement time may cause the market to experience supply pressure in the short term, while new cash flow has not been added correspondingly. This is a factor that investors need to pay attention to besides the positive long-term meaning of upgrading.
According to the assessment of MBS Securities Company, the market currently has no supporting momentum in the short term. Notably, despite receiving news supporting market upgrades, liquidity has returned to the lowest level since the beginning of the year, showing that investors have little expectation of the market having "waves" and even more reason to "wait" for stronger support measures.
MBS Securities also noted the differentiation between the diễn biến of the index and each stock group. Therefore, in the short term, the riêng diễn biến of each stock and the ability to hold technical support zones may be more important than just looking at the fluctuations of VN-Index.
With foreign capital flows, active capital flows will consider both business prospects, exchange rate fluctuations and USD yields, while index-based capital flows have their own disbursement schedules and portfolios. It is estimated that the process of joining FTSE GEIS - FTSE Russell's global stock index, may bring about 1.8 billion USD of passive capital in a year, but in September it was only about 180 million USD. Therefore, experts believe that there is no expectation that upgraded cash flow will immediately compensate for all investors' hesitation.
Conversely, a result that the FED is less tough than expected, along with cooling oil prices, may help improve sentiment, and it is necessary to observe real purchasing power after the information is released to assess the market's transition to a sustained upward momentum.
For large-scale funds, one round of capital flows after the upgrade is not enough to change long-term investment decisions. Funds are also interested in whether Vietnam continues to be positively assessed by international index organizations and how the market's capital absorption capacity is improved. Therefore, the period after September will be an important time to assess whether the upgrade only creates one round of capital flows at a time or opens up a more sustainable attraction trend.
