Topline: The stock market’s explosive growth this year—the S&P has risen more than 27%—means that 2019 is shaping up to be one of the best years for investing in recent history, which has been a boon for the leading tech giants that have seen their market caps grow rapidly.

But the boom times have also left some competitors behind, among them some of the country’s biggest pharmaceutical, chemical, and consumer goods companies, reflecting changing times.

Crucial stat: If the S&P 500 index exceeds 29.6% before the end of December, it will be the best yearly return in six years, and if it passes 31%, the best in 22 years, according to analysis from CNBC.

Here are the ten companies that saw their market cap gain the most in 2019,* with a combined total increase of nearly $2 trillion:

Apple stock had a blockbuster year in which its market value rose by $497 billion to nearly $1.25 trillion, as its stock hit numerous new record highs in the second half of 2019. The company benefited from strong product sales and its entry into the streaming wars with Apple TV+.

Microsoft, another top-performing tech giant, which has greatly expanded its cloud business this year, saw it's market cap rise by $408 billion to a total of $1.19 trillion— running neck-and-neck with Apple for the title of the world’s most valuable company.

Google, which still dominates in digital advertising and search—though it’s also expanding into areas like artificial intelligence and self-driving cars—has seen its market cap go up by $214 billion to almost $934 billion.

Facebook has continued to attract more revenue by adding new users to its core platform as well as to services like Instagram and WhatsApp, despite potential regulatory scrutiny on the horizon. It has gained $213 billion in market value since the beginning of 2019, for a total of $587 billion.

Amazon has seen its market value go up by almost $150 billion—to a total of $887 billion—this year, thanks to strong growth in its cloud-computing (Amazon Web Services) and advertising businesses.

Other stocks that have made big gains in market value this year include financial services companies like Visa ($115 billion), JPMorgan Chase ($111 billion) and Mastercard ($106 billion).

The companies rounding out the top 10: Disney ($100 billion), which launched its new and highly successful Disney+ streaming service in the fall, as well as Procter & Gamble ($82 billion), which has cut costs and consolidated its brands this year.

Here are the top 10 companies which lost the most market value in 2019,* for a combined loss of just over $140 billion:

DuPont, previously the world’s largest chemical conglomerate, spun off numerous businesses throughout the year, including its commodity chemical subsidiary Dow and agricultural unit Corteva, which slashed the company’s market cap by more than half in April. Its market value has fallen nearly $34 billion over the course of the year, down to a total of $47.5 billion.

Pfizer saw its market value fall just over $33 billion—to $218 billion—in 2019. That’s due to declining sales and the merger of its Upjohn generic drugs division with Mylan earlier in the year, which generated a negative reaction from Wall Street analysts.

Kraft Heinz, one of billionaire investor Warren Buffett’s biggest holdings (almost a 27% stake), saw its stock fall more than 30% in late February after the company wrote down the value of iconic brands Kraft and Oscar Mayer by more than $15 billion. Shares haven’t really recovered since, and the company lost $13.5 billion in market value this year.

Walgreens Boots Alliance: The international drug store chain’s market cap has decreased $13.1 billion this year, to $52 billion, as the company faces heightened concerns about competition from online retailers, leading it to slash costs and explore a massive potential leveraged buyout from a private company.

Occidental Petroleum has seen its market value fall $11.5 billion, as Wall Street investors worry about its large debt load stemming from a $37 billion takeover of Anadarko Petroleum earlier this year, as well as slumping energy stocks in general.

Other stocks that have seen big decreases in market value this year are industrial products manufacturer 3M ($10.7 billion), real estate investment trust Simon Property Group ($7.4 billion) and medical implant device maker Abiomed ($7.0 billion).

Rounding out the top ten: Biogen ($5.6 billion), which focuses on treating neurological diseases, and IT services specialist DXC Technology ($4.7 billion).