A share split leaves every holder with more shares each worth proportionally less, and the company's total value unchanged. Something that alters nothing financially still happens for identifiable reasons.
The arithmetic is deliberately neutral
In a split, each existing share becomes several, and the price adjusts by the same factor. A holder's total stake is identical before and after.
Nothing about the underlying business changes either. Earnings, assets and cash flows are unaffected, and per-share figures are restated so that ratios remain comparable across the event.
Because no value is created, a split is best understood as a change in the denomination of ownership rather than a corporate action with financial substance.
Accessibility is the practical motive
A very high share price makes small purchases awkward, since an investor with a modest amount to invest may not be able to buy a whole share at all.
That matters for employee share schemes, dividend reinvestment and any arrangement that allocates a fixed sum rather than a fixed number of shares, all of which work more cleanly at lower prices.
Fractional trading has reduced this constraint considerably, which is one reason some very highly priced companies have declined to split for decades without apparent harm.
Liquidity and option markets respond
Lower prices tend to increase the number of shares traded and can narrow spreads in relative terms, since the minimum price increment becomes a smaller fraction of the price.
Options contracts typically cover a fixed number of shares, so a high share price makes each contract expensive and puts option strategies out of reach for smaller participants.
Splitting reduces the notional size of each contract, which usually broadens participation in the options market around the company.
The signal often matters more than the mechanics
Companies generally split after sustained price appreciation, so the announcement conveys that management considers the higher level durable rather than temporary.
Boards are reluctant to split shortly before a decline, since reversing course is awkward, and that reluctance gives the decision a modest informational content.
Any price reaction reflects that inference about management's confidence, not the split itself, which is why the effect is inconsistent and frequently fades.
Reverse splits carry the opposite message
A reverse split consolidates several shares into one and raises the price proportionally, and companies usually do it to satisfy an exchange's minimum price requirement.
Because the requirement is only reached after a substantial decline, the action is commonly associated with businesses in difficulty rather than with routine housekeeping.
The arithmetic is just as neutral as an ordinary split, but the circumstances that prompt it are not, which is why the two are received so differently.