Microsoft shares close in on a record after a four-month rally

What happened

Microsoft shares are on pace to close at a record for the first time in nearly a year, Bloomberg reported on Tuesday. The software maker's rally has now been running for four months and is gaining momentum as the AI rally builds.

Why it matters

Many people start investing with an index fund, and in an index weighted by market value the biggest companies carry the most weight. When one of those giants climbs, your fund can go up even if most other companies barely move. The flip side is that the same few giants can drag a fund down, so it is worth knowing which companies actually make up what you own.