Alphabet's soaring stock just pushed it above a $1 trillion market cap. Here are the 11 highest-valued public companies.

• Alphabet is the latest company to reach a $1 trillion valuation in public trading after closing at a record high Thursday.
• The record level adds a third tech company to the list of firms with four-comma valuations.
• The list of highest-valued firms remains tech-heavy, though oil behemoth Saudi Aramco maintains the world's highest market cap at $1.84 trillion.
• Here are the 11 highest-valued public companies in the world, ranked in ascending order.
• Visit the Business Insider homepage for more stories.

Alphabet is the latest firm to join the small group of companies with market caps higher than $1 trillion, further cementing the tech sector as the highest valued in public markets.

The Google-parent's Thursday close set the stock high enough to notch a valuation above the four-comma threshold. The record level also helped push Big Tech - the five stock group comprised of Alphabet, Amazon, Apple, Facebook, and Microsoft - past a $5 trillion market valuation for the first time.

The S&P 500's information tech sector is dominating all of the index's other subgroups in the year-to-date, after already posting a 50% return in 2019. The group's massive run-up was primarily driven by Apple stock, as the iPhone maker gained more than 80% last year.

Apple was the first company to reach a $1 trillion valuation in August 2018, and held the crown as the highest-valued public company as recently as December 11. The tech giant lost its top spot when Saudi Aramco debuted on public markets with a record-breaking $1.7 trillion valuation.

Aramco stock proceeded to surge high enough to hit a $2 trillion valuation before paring gains through January.

Here are the 11 highest-valued public companies around the world, ranked in ascending order. Data is as of 3:00 p.m. ET on January 17.