Singapore's Straits Times Index finished September 11 at 5,695.93, up 0.1%, according to The Business Times. Yet the broader market recorded 340 decliners against 215 gainers. Those figures are not contradictory. The index reflects the performance and weights of its constituents, while the number of rising and falling shares describes a different feature of the market.
Why three banks can change the picture
DBS, OCBC and UOB all rose in the reported session. Market-capitalisation weighting gives larger companies more influence than smaller ones. Breadth simply asks how widely a move is shared. An index can therefore gain when several influential names rise, even though a portfolio concentrated in smaller industrial or consumer businesses falls.
A useful comparison for the weekend
Check the bank weight in your fund's latest holdings before calling it a diversified bet on every part of Singapore. For illustration, a portfolio with 40% in one sector gains 0.8% from that sector if it rises 2%, assuming the remainder is unchanged. That is a weighting example, not the STI's actual bank weight.
Compare total returns, including distributions, over the same period and currency. A single close tells us where prices ended; it does not prove that oil-related risks or earnings pressures have gone away. If your holding behaves differently from the STI, inspect its sector exposure before assuming the fund has malfunctioned.