VIX Leads Proprietary Net Selling as Foreign Investors Dump VND 1.65 Trillion

Overview

Foreign investors net sold VND 1,648 billion on HOSE in the week ended September 11, while proprietary trading desks at securities firms net sold VND 551 billion, according to weekly exchange data. VIX (HOSE) alone accounted for VND 484 billion of the proprietary selling, and its shares fell 5.4% to VND 13,250. The outflows came as the VN-Index lost 57.87 points, or 3.12%, to close at 1,795.21.

Key Facts

• VN-Index fell 57.87 points (-3.12%) on the week to 1,795.21; HNX-Index dropped 3.49% to 272.68 and UPCoM-Index fell 1.47% to 126.47.
• Foreign investors net sold VND 1,648 billion on HOSE; proprietary desks bought VND 2,267 billion and sold VND 2,818 billion, for net selling of VND 551 billion.
• VIX accounted for VND 484 billion of proprietary net selling, all via order matching, with the stock down 5.4% to VND 13,250.
• The securities sector was net sold VND 470 billion by proprietary desks, less than VIX alone, implying the remaining listed brokers were net bought.
• MCH saw VND 69 billion and MBB VND 44.5 billion of proprietary net selling; VCB led net buying at VND 73.5 billion, followed by MWG at VND 40.1 billion and TCB at VND 32.9 billion.
• HOSE trading value for the week reached VND 76,571 billion, averaging VND 15,314 billion per session, down from VND 18,669 billion in the final week of August.
• The State Securities Commission approved VIX’s adjusted charter capital on September 10, following completion of its 2025 stock dividend payment in late August.

What Happened

HOSE recorded 83 gainers against 304 decliners for the week. The sharpest session was Friday, September 11, when the VN-Index fell 34.02 points (-1.86%) with 28 of 30 VN30 constituents lower. Vietcombank Securities (VCBS) attributed the late-session pressure to intensified selling in banking, real estate and securities names during the final 15 minutes and the closing auction, pushing the index to its intraday low.

Proprietary desks traded 108 tickers, net buying 50 and net selling 56. VIX’s VND 484 billion of net selling was executed entirely through order matching rather than put-through transactions. Halcom Vietnam (HID) led weekly gains at 29.3%, while First Real (FIR) fell the most at 19.8%. The securities group was broadly excluded from the advance, with 20 of 21 HOSE-listed brokers declining.

Market Context

VIX trades on HOSE at VND 13,250 as of September 11, the deepest weekly decline among the 20 tickers with the largest proprietary net flows. The stock’s move tracked a sector-wide retreat: proprietary desks net sold VND 470 billion of securities names in aggregate, meaning VIX’s own selling exceeded the entire group’s net outflow. Banking names appeared on both sides of proprietary flows and finished nearly balanced at VND 11.3 billion net bought, though MBB, ACB, CTG and STB ranked among the ten most heavily net-sold tickers. VCBS said weekly selling pressure came mainly from large-cap securities, banking and Vingroup-related stocks, while cash rotated into mid- and small-caps in industrial parks, retail and oil and gas.

Strategic Significance

VIX’s outsized share of proprietary selling matters because it coincided with the completion of a 2025 stock dividend and a September 10 charter-capital adjustment approved by the State Securities Commission. A capital increase via share issuance dilutes per-share metrics and can prompt short-term repositioning by desks that held the stock into the event. The concentration also cuts against the sector narrative: if proprietary desks were exiting Vietnamese brokerage exposure broadly, the remaining 20 listed securities would not have been net bought. Instead, the data points to VIX-specific flow rather than a sector-wide de-risking, leaving the question of whether the selling reflects post-dividend arbitrage or a reassessment of VIX’s earnings base.

What to Watch

• VIX’s September proprietary flow data to see whether the VND 484 billion weekly net sale extends or reverses.
• Foreign net flow on HOSE for the week of September 14-18, after the VND 1,648 billion outflow.
• VCBS and BVSC weekly strategy notes for revised support levels; BVSC has already recommended reducing portfolio exposure.
• VIX disclosures on post-dividend share count and any updated charter capital figures.
• Whether the VN-Index holds the 1,795 level or tests lower supports on continued large-cap selling.