The U.S. presidential election is by far the most expensive political race in the world, especially when compared with countries that have strict regulations on campaign funding and expenses. While campaigns are exceedingly costly, individual politicians, too, are often among the wealthiest Americans in the country.

Presidential candidates can expect very little privacy — in their personal life and with their finances. While candidates are not required to make their tax returns public, the practice has become common since the late 1970s. Based on recently disclosed tax returns and financial disclosures, the candidates’ assets range from Scott Walker, who is worth as little as $36,000 to Donald Trump, who has an estimated net worth of $2.9 billion — by far the highest of any presidential candidate.

Click here to see the net worth of each presidential candidate.

Estimating a candidate’s net worth is difficult because reporting exact values is not required. Instead, candidates may disclose their assets and income in a range. Further, candidates do not necessarily report all their assets. For instance, candidates do not need to disclose their personal real estate, and property values. Jeb Bush opted to omit assets generated by several holding companies, for example.

In addition, the net worth of a presidential candidate does not necessarily determine the financial strength of the associated campaign. Campaign expenditure in the United States has increased even more since 2010, when the U.S. Supreme Court ruled that political spending is a form of free speech. This opened the door for corporations and unions to sway the voting public via indirect, but unlimited, contributions.

Some candidates’ campaign funds are far greater than their net worth, while others are far lower. Bernie Sanders is one of the poorest presidential candidates, yet his campaign has raised over $16.4 million so far. Jeb Bush, on the other hand, has raised nearly $12 million, but his maximum estimated net worth is valued at nearly twice that.

Still, the wealth of a presidential candidate seems to matter a great deal. Fundraising is crucial for candidates, and the candidates who are able to focus more on earning votes and less on raising money have an advantage. Obama and Mitt Romney’s campaigns each raised just over $1 billion in 2012. Even by the lowest estimates, Donald trump does not need to raise a single dime from here through election day to have more funds available than both 2012 candidates combined. To date, Trump has self-financed roughly 95% of his campaign’s spending. Just 6% of Bernie Sanders’ campaign spending has come out of the senator’s pocket.

To identify the net worth of each presidential candidate, 24/7 Wall St. reviewed the most recent tax filings of the highest-polling Republican presidential candidates, as well as the two highest-polling Democratic presidential candidates. Each candidate’s poll is an average of four widely recognized surveys of American opinion, including CNN and Fox.  In order to determine ranges for each of these candidates we relied on the best available data from at least one of the following sources: analyses from third-party sources of personal financial disclosures provided to the Federal Election Commission (FEC), statements made by the candidates’ campaigns, and in the case of current members of congress, specific net worth values obtained by The Center for Responsive Politics through 2013 tax filings. The Center also provided campaign finance figures. We also considered campaign contribution totals, which each candidate for president is required to submit to the Federal Election Commission (FEC).

These are the top contenders for president and how much they’re worth.

13. Scott Walker
> Net worth: -$243,992 — $69,998

Between Trump and some of the other wealthier candidates like Bush and Fiorina, the 2016 Republican race may have the highest combined net worth of any primary in history. On the other end of the spectrum, however, is Wisconsin Governor and presidential hopeful Scott Walker, who appears not only to have a relatively small net worth, but also most estimates point to Walker being tens of thousands of dollars in debt. According to one source, Walker is currently paying off his credit card debt at an interest rate of close to 30%. In addition, Walker has taken on enormous student debt for his children.

As Governor, he garnered national attention by implementing right-to-work legislation, which significantly limited the power of labor unions in the state. Walker appears to be roughly in the middle of the pack for financial support among Republican candidates, raising an estimated $26.2 million.

ALSO READ: The Next 11 States to Legalize Marijuana

12. Marco Rubio
> Net worth: $57,018 — $829,999

Marco Rubio was a member of the Florida House of Representatives from 2000 to 2008. He has represented Florida in the U.S. Senate since 2010. Rubio’s estimated net worth, according to the Center for Responsive Politics, of $443,509 is low compared to other U.S. congress members, and it is nearly the lowest compared to other GOP presidential candidates. However, the Florida senator’s modest net worth has been scrutinized due to his ties with Norman Braman, a billionaire auto dealer who, in addition to funding many of Rubio’s personal endeavors, is by far Rubio’s single largest campaign donor. Large individual donations make up 70% of Rubio’s current campaign funds, which so far total around $10 million.

11. Bernie Sanders
> Net worth: $194,026-$741,030

In 2013, Bernie Sanders had an average estimated net worth of $330,507, well below other prospective presidential nominees and among the lowest compared with other members of Congress. The Vermont senator, who is the longest-serving independent in U.S. history, is a self-identified socialist. He is seeking the Democratic nomination, however, and is the most popular Democratic candidate after Hillary Clinton. In keeping with Sanders’ stated intention of starting a grassroots movement, more than 90% of his campaign contributions have come from individual donors. Sanders’ campaign speeches have drawn record numbers of attendants. Most recently, 19,000 people watched Sanders speak at an NBA arena in Portland, Oregon, the largest political event compared with all other candidates so far this election season.

10. Rand Paul
> Net worth: $683,036 — $2.0 million

Rand Paul, a Kentucky senator and ophthalmologist, is widely regarded as the most libertarian-minded presidential candidate. He, like his father Ron Paul, has long advocated for states’ right to operate without federal influence. Unlike most of his GOP running mates, the bulk of Rand Paul’s campaign contributions come from small, individual donations, which totalled more than $3.4 million as of June. While Paul is wealthier than most members of Congress, he is by no means the wealthiest. Paul’s average net worth of $1.3 million pales in comparison with that of his fellow Kentucky senator, Mitch McConnell, for example, who has an estimated average net worth of over $30 million.

9. Chris Christie
> Net worth: At least $1.5 million

Many thought New Jersey Governor Chris Christie was considering a run for the White House in 2012, but it would be another election cycle before this became a reality. Christie may be facing an uphill battle due to a 2013 scandal when members of his staff closed several lanes of traffic on the George Washington Bridge, causing severe traffic problems in Fort Lee. It is speculated that this was done as a means of political retribution against Fort Lee Mayor Mark Sokolich, who had not supported Christie’s gubernatorial reelection. Christie’s financial disclosure form shows the Governor is worth at least $1.5 million, but the maximum listed value for each item on the form was $500,000. It is likely his wife, who is a Wall Street executive and by many accounts a bigger earner, is worth significantly more than $500,000. When Christie released his net worth in greater detail in 2009 when he was attorney general for New Jersey, his total estate was valued at $3.8 million.

8. Ted Cruz
> Net worth: $1.7 million — $4.5 million

Ted Cruz, the son of a Cuban immigrant who became an oil businessman, has built his campaign around the promise of the American dream. Cruz is now an Ivy League-educated lawyer, a Tea Party-backed Texas senator, and a GOP presidential candidate. Cruz is a divisive candidate, notable for his role in the 2013 federal government shut down. He is skeptical that global warming poses a threat, is an opponent of equal marriage rights, and is also an outspoken critic of the Affordable Care Act. Far from being the wealthiest U.S. congressman, he still falls well within the top 50% with an average net worth of just over $3 million.

ALSO READ: America’s Best Companies to Work For

7. Mike Huckabee
> Net worth: $7 million — $23 million

Mike Huckabee, the former governor of Arkansas, is running for his second presidential campaign, after losing the 2008 republican presidential primary to John McCain. Leading up to that first election, The New York Times reported that Huckabee’s assets were valued at less than $700,000. It appears that Huckabee was able to capitalize on the fame he earned during the previous race. The former governor enjoyed lucrative speaking appearances, published several books, and began hosting his own radio show on ABC. The 2016 presidential hopeful and his wife recently moved into an estimated $3 million home in Blue Mountain Beach, Florida. Huckabee’s net worth has been estimated as high as $23 million.

6. Ben Carson
> Net worth: $8.0 million — $19.6 million

Ben Carson is a former neurosurgeon. He was the head of pediatric neurosurgery at Johns Hopkins for 29 years. Carson is famous for being the first to separate conjoined twins for the first time, and successfully completing other difficult surgeries. Carson has an estimated net worth of at least $8 million. Some of Carson’s wealth comes sales of the numerous books he has published, including Gifted Hands, which was adapted for a 2009 film. Carson’s income sources also include a salary from his professorship at Johns Hopkins.

ALSO READ: How Obamacare Increased Coverage in Every State

5. John Kasich
> Net worth: $9 million – $22 million

Ohio Governor and presidential hopeful John Kasich remains a long shot at the moment to become the Republican nominee in 2016. Kasich is polling at an average of approximately 4%, which is 10th in the field. He has raised $11.7 million, according to The New York Times, which places him 10th among candidates of both parties for campaign finance. Before entering the realm of politics, Kasich made his living as a partner at the now infamous Lehman Brothers. Current estimates put Kasich’s net worth between $9 million and $22 million.

4. Hillary Clinton
> Net worth: $11 million — $53 million

In 2001, Hillary Clinton became the first female senator to represent New York State. After serving as Secretary of State in the Obama administration from 2009 to 2013, Clinton announced her candidacy for president yet again this past April. Clinton is currently outspending and outpacing her closest competitor, Senator Bernie Sanders, in fundraising. The Clinton campaign has raised more than $47.5 million, not including super PAC funding, and spent nearly $18.9 million — significantly more than the $16.4 million and $4.8 million the Sanders campaign has raised and spent, respectively. However, while 69% of of Sanders’ campaign contributions have come from small individual donations, while only 17% of Clinton’s contributions have come from small individual donations.

Hillary Clinton is worth at least $11 million, and as much as $53 million, which includes her husband Bill’s substantial net worth. Much of the net worth Hillary is directly responsible for includes the income she earned through investments, her book, and speaking fees since her time working for the government.  Over the past several years, Clinton and her husband have spent hundreds of thousands of dollars on summer rentals in the Hamptons. Some of Clinton’s influential campaign donors have urged her not to rent another home in the Hamptons while campaigning for fear she could be dubbed an elitist.

3. Jeb Bush
> Net worth: $19 million — $22 million

Son of one former president and brother of another, former Florida Governor Jeb Bush is one of the leading GOP presidential candidates for the 2016 election. When Bush left the Florida governor’s office in 2007, he was worth an estimated $1.3 million. In his years since holding public office, between the lecture circuit and consulting jobs, Bush has amassed a small fortune. Today, Bush’s campaign aides estimate his net worth to be between $19 million and $22 million. Earlier this year, The Boston Globe reported that the former governor is having a vacation home built on a $1.4 million piece of property in Kennebunkport, Maine. Though Bush is currently trailing Trump in the polls, his campaign has raised more than $11.4 million — about six times the amount the Trump campaign has raised.

2. Carly Fiorina
> Net worth: $59 million

The first female CEO of a top 20 company as ranked by Fortune, Carly Fiorina is running for president under the slogan “We must once again become a nation of limitless possibility.” The former Hewlett-Packard CEO has been attempting to spin her previous experience as a qualifying credential. However, Fiorina was fired from her executive role at HP in 2005 after an ill-advised merger with Compaq and a 50% drop in the company’s stock price. Fiorina is the only woman vying for a spot on the GOP ticket and one of only two women in the entire race. In June, Fiorina claimed a net worth of $59 million. The figure includes the net worth of Fiorina’s husband, Frank. Unlike most other candidates, Carly and Frank Fiorina disclosed precise value of their assets.

1. Donald Trump
> Net worth: $2.9 billion — $10 billion

Donald Trump is far and away the wealthiest individual running for the presidency. His precise net worth, however, is difficult to gauge as media estimates, his FEC financial disclosure, and statements from his own campaign vary widely. Bloomberg and Forbes estimated Trump’s net worth at $2.9 billion and $4 billion, respectively. Trump, meanwhile, claimed a net worth of $10 billion. Trump is capable of funding his entire campaign himself. So far in the campaign, he has donated $1.8 million to himself, accounting for 95% of all his campaign funds.

Trump has made numerous inflammatory remarks regarding women, immigrants, and China among other targets — remarks that have received mostly bad press but that have also helped him gain popularity. The real estate tycoon is the Republican frontrunner, commanding roughly 22% of GOP voters, roughly double the support garnered by next-in-line Jeb Bush.

Now read the Net Worth of the U.S. Presidents: Washington to Obama

[Editor’s note: the net worth of Chris Christie has been added to this report to reflect his rise in the polls. Bernie Sanders’ and Hillary Clinton’s numbers have also been updated.]

Thank you for reading! Have some feedback for us?
Contact the 24/7 Wall St. editorial team.