Settling 2026’s Biggest MPF Rotation: HK$12bn Chased US Equities, HK$10.26bn Fled Hong Kong — Momentum Won September, Lost 14.4 Points Year-to-Date

The core proposition

The largest collective fund switch in Hong Kong’s MPF system this year now has a scorecard.

GUM’s August market report (published 18 September 2026) recorded the scale of the rotation: year to date, US equity funds had absorbed over HK$12 billion of net inflows — HK$2.24 billion in August alone, the fifth consecutive month topping the inflow table. Over the same period, Hong Kong equity funds (including index trackers) suffered about HK$10.26 billion of net outflows, HK$1.85 billion in August — the most-redeemed equity category of the year. GUM’s strategy and investment analysis director put it bluntly: members allocate by “closely tracking market performance and sentiment.” In plain English: performance chasing.

September’s numbers are now in (GUM through 18 September, MPF Ratings through 21 September). The verdict first, the ledger after:

The chasers won September — US equities were the most resilient asset class while Hong Kong equity funds fell another 2.8%. But stretch the ledger to year-to-date and the same money lost 14.4 percentage points: US equity funds are up 10.1% YTD; the real leader, Asian equity funds, is up 24.5%. The cruelty of momentum trading: you chased the right direction and bought the wrong market.

X-ray: flows versus returns

(Performance: GUM’s September report through 9/18; MPF Ratings’ 24 September report through 9/21. The two reads disagree on the US September figure — +1.275% versus -0.5% — a cutoff-date and methodology difference, but both conclude the same thing: US equities were September’s most resilient asset.)

Three things the data exposes:

First, September’s chase genuinely “worked.” Anyone who moved money from Hong Kong equity funds into US equity funds dodged roughly 3 percentage points in a single month (GUM’s read: -0.5% versus -2.8%). Against the HK$10.26 billion rotated out of Hong Kong equities YTD, that one month of timing was worth about HK$300 million. The question: was that the first correct call in five months of chasing, or just luck?

Second, the YTD ledger tells a completely different story. US equity funds’ +10.1% sounds respectable — until you see Asian equity funds at +24.5%, powered by strong but volatile Korean and Taiwanese tech returns (MPF Ratings’ words). The chasers bought “past performance,” and the market with the best past performance was Asia — ranked only fourth in the inflow table. HK$12 billion chased a +10.1% market and missed a +24.5% one.

Third, the experts were warning at the exact peak of the inflows. In the same GUM report, the firm’s chief investment officer said US equities currently offer “little room for error,” advising anyone worried about valuations to diversify through global funds; the managing director went further, tipping Greater China and Hong Kong equity funds to “stabilise and improve” in Q4. Fund flows ran directly against professional judgement — a textbook behavioural-finance tableau.

The compounding cost: what 14.4 percentage points is worth

Translate the percentages into human terms.

HK$12 billion x 14.4% = HK$1.728 billion. That is the YTD opportunity cost of the rotation relative to Asian equity funds — HK$1.7 billion spent on a single lesson: momentum is a rear-view mirror, not a windscreen.

In per-member terms (illustrative): 14.4% of the average balance of HK$343,242 is HK$49,427 — roughly eighteen months of an ordinary member’s total contributions.

Stretch it to compounding scale. Contributing HK$5,000 a month for 30 years: a 7% annualised return ends at about HK$6.1 million; 6% ends at about HK$5.02 million — one percentage point of annualised return is worth HK$1.08 million over 30 years. And the annual “behaviour tax” that chasers pay, measured by Morningstar’s Mind the Gap 2026, is 1.2 percentage points — more than a full point. In other words, the long-run cost of the chasing habit exceeds this year’s entire US-versus-Asia gap.

There is one overlooked line in the ledger: alongside US equity funds in August’s top-five inflow list sat the DIS Core Accumulation Fund — the default strategy “continues to be sought after,” in GUM’s words. Among the same membership, some chased momentum while others handed their money to the do-nothing fund annualising about 7.3% since 2017. The latter group did nothing all year.

The playbook: replace “switching” with “rebalancing”

The fix is not to never switch — it is to switch for a different reason.

First, replace chasing discipline with rebalancing discipline. Set a target allocation tied to age and years to retirement (say 80/20 equities-to-bonds at 35, de-risking from 50), and rebalance once or twice a year — selling what has run up, buying what has lagged. Rebalancing is the mechanisation of buy-low-sell-high; chasing is the emotionalisation of buy-high-sell-higher.

Second, diversify into the uncomfortable. Asian equity funds’ YTD-leading +24.5% proves the value of regional diversification; re-read the CIO’s advice: if US valuations worry you, use global equity funds to dilute single-market risk. Genuine diversification always means buying the market that looks unappealing right now.

Third, forward-pricing protection on execution. MPF switches execute at unknown T+1 prices, so stage large switches in tranches; treat the Fed meeting on 27–28 October and the US midterms in November (GUM’s flagged Q4 variables) as no-switch zones.

Fourth, switch a different thing. Rather than chasing fund momentum, chase fee certainty: with full portability’s first phase live and the annual ECA window, moving balances to the market’s lowest-FER scheme saves a guaranteed 0.5–1 percentage point a year — money that requires no market forecast, only a form.

Momentum won September, but September is only one month. Stretch the ledger, and the market always taxes the undisciplined.

Sources: GUM August 2026 MPF Market Analysis Report (18 September 2026, via Eastmoney, on.cc and am730 syndication), MPF Ratings 24 September 2026 report (data through 21 September), Morningstar Mind the Gap 2026. Illustrations assume gross returns before fees; past performance is not indicative of future results.