The PSE Composite Index, or the PSEi (previously PHISIX), is a stock market index of the Philippine Stock Exchange (PSE) always consisting of 30 of the largest companies traded on the stock exchange.^[1] This is in contrast to the PSE All Shares Index which is an index of all stocks traded on the PSE.

The highest closing value was 9,041.20 on Friday, January 26, 2018.^{[citation needed]} The highest intraday value was 9,078.37 on Monday, January 29, 2018.^{[citation needed]}

It is the PSE's only broad-base index and is seen as an indicator of the general state of the Philippine business climate,^[2] although its reliability as an indicator of the state of the broader Philippine economy has been questioned.^{[by whom?][3]}

The PSE revises the list at least twice a year based upon requirements that include a minimum public float level of 20% (increased from 12% in 2018) and criteria for market liquidity and market capitalization.^[4]

The following formula is used by the PSE to calculate the index's value:

${\displaystyle {\mathsf {PSE\ Index_{t}={\textstyle \sum _{i=1}^{n}(P_{i}\times S_{i}\times F_{i})\displaystyle \over \ b}\times PSE\ Index_{t-1}}}}$^[5]

Where:

n = Total number of component companies (30)

${\displaystyle {\mathsf {P_{i}}}}$ = Closing price of company i at day t

${\displaystyle {\mathsf {S_{i}}}}$= Available shares of company i at day t

${\displaystyle {\mathsf {F_{i}}}}$= Company free float level (0 to 1), where 1 means 100% free float.

b = Free float-adjusted market capitalization base

These are current as of February 2022:^[6]

• PSE All Shares Index, index of almost all shares traded in the PSE