The latest compilation adjustments to the major indices on the Shanghai Stock Exchange, which took effect on Monday, will help further cushion market volatility and lower risks, which is of great importance at a time of global downward pressure, said experts.
专家表示，上交所主要指数最新编制调整于这周一正式生效，此举有助于进一步缓释市场波动、降低风险，在全球经济承压背景下意义重大。
Two major changes have been implemented, according to the latest revision details announced in late September.
根据 9 月末公布的最新修订细则，本次调整包含两大改动。
First, a constituent's weight is now capped at 15 percent. Second, the timing for removing risk-warning counters from the indices has been moved earlier. Previously, a stock was taken from the index on the first trading day after the second Friday of the month following the date the risk warning took effect. Now it is dropped on the first trading day after the second Friday of the month following the date the risk warning was issued.
第一，单只成分股权重上限设为 15%；第二，指数剔除风险警示股票的时间节点提前。此前，股票在风险警示生效日后次月第二个周五后的首个交易日调出指数；新规调整为，在风险警示公告发布日后次月第二个周五后的首个交易日调出指数。
Tian Lihui, a finance professor at Nankai University, compares the two practices to a "flow-control valve" and "filter" for the indices. The 15-percent cap can prevent one behemoth company from "kidnapping" the overall market performance due to its huge size. Bringing the removal date forward ushers disqualified counters out of the sample pool more efficiently.
南开大学金融学教授田利辉将这两项调整比作指数的 “流量控制阀” 和 “过滤器”。15% 的权重上限能够避免体量巨大的巨头个股绑架整体指数表现；提前调出时间则可以让不合格标的更高效地退出样本池。
"Amid higher downward pressure, the market is more sensitive to any factors that might aggravate fluctuations. The latest adjustments can cleanse the index ecosystem at the algorithmic level, ensuring the indices objectively and fairly reflect overall quality even in a weak market," Tian said.
田利辉表示：“下行压力加大时，市场对可能加剧波动的因素更为敏感。本次调整能够从编制规则层面净化指数生态，保证即便在偏弱行情中，指数也能客观公允地反映市场整体质量。”
Four major indices — including the SSE Composite Index and the STAR Composite Index — are subject to the 15-percent cap limit.
上证综合指数、科创综合指数在内的四大指数执行 15% 的权重上限规则。
Guo Shiliang, an independent financial commentator, said the new rule is mainly an adjustment to the compilation rules of the SSE series of indices rather than a cap applied uniformly on all A-share market indices.
独立财经评论员郭施亮表示，新规主要是针对上交所系列指数编制规则的调整，并非对全部 A 股指数统一设置权重上限。
Given that the SSE Composite Index's weight composition is relatively balanced and the weight of any single heavyweight stock is far below the 15-percent cap, the impact on the SSE Composite Index's constituent shares is fairly limited, and the room for subsequent constituent weight adjustments will be relatively small. By contrast, the impact on weight adjustments for the tech-focused STAR Composite Index's constituent stocks will be larger.
由于上证综指权重结构相对均衡，单只权重股占比远低于 15% 上限，本次调整对上证综指成分股影响有限，后续权重调整空间不大。与之相比，主打科技赛道的科创综合指数成分股受到的权重调整影响更大。
"Take memory chipmaker ChangXin Memory Technologies as an example. Prior to the new rule, the company's market-cap weight would have exceeded 20 percent once formally added to the STAR Composite Index, well above the 15-percent cap. The new rule will effectively reduce the index's overreliance on any single stock," Guo said.
郭施亮称：“以长鑫存储这家存储芯片企业为例，新规落地前，若其纳入科创综合指数，市值权重占比将超过 20%，显著高于 15% 上限。新规将有效降低指数对单一个股的过度依赖。”
As for the adjustment to risk-warning stocks, Yang Delong, chief economist at First Seafront Fund, said that the liquidity of these companies may deteriorate in a weak market.
关于风险警示股票调出规则的调整，前海开源基金首席经济学家杨德龙表示，弱势行情下这类标的流动性容易恶化。
Bringing the removal date forward helps shorten the time that passive products are stuck holding problem stocks and reduces the impact costs of concentrated rebalancing, thereby protecting the interests of investors holding funds that track the index, Yang said.
杨德龙认为，提前调出时间，可以缩短被动产品被动持有问题股票的周期，降低集中调仓带来的冲击成本，从而保护跟踪该指数的基金持有人利益。
This move represents another major adjustment in SSE indices since July 2020, when special treatment stocks — those with abnormal financial or operational situations — were removed from the sample pool and the inclusion of new stocks was delayed.
这是上交所指数自 2020 年 7 月之后又一次重大调整。2020 年 7 月调整将财务或经营状况异常的 ST 股剔除样本池，并延后新股纳入指数时间。
Analysts from Guosen Securities said that the indices' long-term representation and investability are likely to steadily improve after the latest changes.
国信证券分析师认为，本次调整后，指数长期的市场代表性与可投资性有望稳步提升。
Wu Xinkun, chief strategist at Guosen Securities, admitted there is short-term downward pressure on the A-share market, which is a combined result of external and internal factors.
国信证券首席策略分析师吴鑫坤坦言，A 股短期承压，是内外多重因素叠加的结果。
Rising oil prices amid geopolitical tensions in the Middle East — as well as the high inflation and interest rates in the United States — have suppressed the pricing of risky assets globally. In the domestic market, investor sentiment for the tech sector has not bottomed out while the market is still awaiting more capital inflows. The market fluctuation is thus magnified, Wu said.
吴鑫坤表示，中东地缘紧张推高油价、美国高通胀与高利率环境，压制全球风险资产估值；国内市场方面，科技板块投资情绪尚未企稳，市场仍在等待增量资金入场，放大了行情波动。
But the outlook on the A-share market's mid- to long-term performance is by no means pessimistic. Companies' profitability is improving, and more long-term capital will be ushered into A shares, providing support for a rebound likely to take place this quarter, he added.
他补充道，但 A 股中长期前景并不悲观，企业盈利持续修复，更多长线资金有望入市，有望为本季度的市场反弹提供支撑。
index /ˈɪndeks/n. 指数
volatility /ˌvɒləˈtɪləti/n. 波动
constituent /kənˈstɪtjuənt/n. 成分股
liquidity /lɪˈkwɪdəti/n. 流动性
