Hang Seng Tech Index to expand to 50 constituents in biggest revamp

Hang Seng Indexes Co. proposed expanding the Hang Seng Tech Index from 30 to 50 constituents, adding a revenue-growth selection track and elevating artificial intelligence to a standalone theme.

"The revamp would give a chance to emerging leaders, particularly across AI, semiconductors and other new-economy areas, to enter the benchmark earlier rather than wait to become very large," said Charu Chanana, chief investment strategist at Saxo Markets.

The consultation paper, released Monday, outlines a two-stream selection mechanism: 40 slots by market value, 10 reserved for companies ranked by trailing 12-month sales growth. The eligible universe narrows to Hang Seng Composite LargeCap & MidCap constituents. Six tech themes are restructured to Digital Platforms & Solutions, Artificial Intelligence, Advanced Hardware, Robotics & Automation, Cloud, and Frontier Technology, with sub-themes expanding from 16 to 24. Sector classification requirements are removed.

About $40.4 billion in passive assets track HSTECH, up from $1.5 billion at launch in 2020. The December rebalancing will force that capital to reallocate — overweight giants face capping back to 8 percent individual weights while newly included AI and hard-tech names absorb inflows. The consultation closes Sept. 18, with final revisions expected by end-September.

The growth track that changes the index's DNA

The revenue-growth stream is the most consequential change. Hang Seng Indexes Co. said in the consultation paper that high-growth tech companies tend to be smaller by market capitalization, and a purely size-based framework systematically excluded them. Existing constituents show median sales growth of 13.8 percent, while the simulated sales-growth additions show 82 percent — nearly six times higher.

The trade-off is visible in the numbers. The smallest constituent's market value drops from HK$28 billion to HK$7 billion. Top-10 weight concentration falls from 70.6 percent to 66.3 percent. Advanced Hardware constituents rise from five to 15, AI from three to six, and Robotics & Automation from eight to 12 — pushing combined Advanced Hardware and AI weighting to 42 percent.

What $40.4 billion in tracking funds means for December

The December rebalancing is a zero-sum reallocation. Alibaba and Xiaomi, with weights of 9.16 percent and 10.59 percent respectively, exceed the 8 percent cap and face forced selling of roughly $260 million and $570 million. Tencent, at 7.67 percent, gains about $72.9 million in relative inflows as others are trimmed.

CICC estimates that Zhipu and MiniMax, if included under the new framework, would each draw about $280 million and $190 million in passive inflows. The flip side: Kingsoft and Kingdee, previously removed from the index, each faced $350 million to $360 million in passive selling — a reminder of the liquidity risk for smaller constituents.

The timing aligns with a broader shift in Hong Kong's technology sector. China's AI large-model weekly call volume has topped the U.S. for 15 consecutive weeks, per OpenRouter data, and DeepSeek V4 Flash consumed 7.22 trillion tokens in a single week. Goldman Sachs raised its 2026 annualized recurring revenue forecast for China AI large models from $10 billion to $13 billion on Aug. 5, while raising Zhipu's 2026 revenue estimate by 35 percent.

The index's fifth revision — and its largest — comes as 81 Hong Kong IPOs raised more than HK$200 billion in 2025, with new-economy companies accounting for 70 percent of first-half listings. Biren Technology listed as Hong Kong's first domestic GPU stock, Zhipu raised about HK$4.3 billion as the first global large-model IPO, and robotics firms including Luoshi Robots followed.

The overhaul doesn't change fundamentals — it changes what the index measures. The question for investors is whether the December rebalancing delivers the promised beta shift, or whether front-running of potential inclusions creates a "buy the rumor, sell the news" dynamic. The September final plan will be the first test; the December rebalancing the second.

This article is for informational purposes only and does not constitute investment advice.