The holidays are a time for relaxing, helping the less fortunate, showering family and friends with love and attention -- and, sometimes, for smiling and nodding through unsolicited stock tips from an overbearing relative who has been sampling the eggnog.

But good advice can make careers and forever change lives for the better. So The Wall Street Journal asked an array of prominent people who manage, invest, study and write about money to share the single best piece of financial advice they ever received -- or gave.

The respondents included investors who collectively have earned billions of dollars for clients and themselves; founders and owners of businesses that are household names; and Nobel laureates who shaped the world's understanding of the forces that drive the stock market.

A leading federal judge who has presided over cases related to the financialcrisis shared his thoughts, as did an agent who has negotiated some of the most lucrative contracts in the history of sports and an adviser who helps clients recover financially after a divorce.

In most cases, the recommendations are easy to follow today. Some reflectconventional wisdom, while some fly in its face. Not every tidbit is consistent with all the others. The responses, some of which were edited for clarity, appear below.

But first, a word of caution: Like all advice, it should be weighed soberly -- ideally, at a good distance from the eggnog.

The best advice I ever got was the buy signal from my dissertation adviser at MIT and later co-author, Franco Modigliani, very close to the bottom of the market in the early 1980s.

I put virtually [all] my portfolio 100% into value stocks then, even though the conventionalacademicwisdom was then that one should be more diversified. I didn't start taking it out substantially until sometime around the turn of the century, around 1999, though I don't remember exactly. I read very carefully his paper with [Richard] Cohn published in the Financial Analysts Journal in 1979, 'Inflation, Rational Valuation and the Market.' It concluded that the stock market was 50% undervalued.

Actually, that was an understatement -- from 1982 to 2000 the S&P 500 total-return index went up something like 20-fold. This investment advice created another miracle for me, for it inspired me to write my article 'Do Stock Prices Move Too Much to Be Justified by Subsequent Changes in Dividends?' published in the [American Economic Review] in 1981 and mentioned prominently in the Scientific Background paper for the Nobel Prize.

So Franco's advice not only got me phenomenal returns, it also helped me win the Nobel Prize. You can't get better investment advice than that.

My labor-law professor once told me: Business and money don't breed warm feelings. Ninety-five percent of what people say about you is going to be negative. And remember, that means that you are doing a good job.

The best financial advice I ever got was from Fred Schwed's classic book, 'Where Are the Customers' Yachts?', first published in 1940. Schwed wrote: 'Like all of life's rich emotional experiences, the full flavor of losing important money cannot be conveyed by literature. Art cannot convey to an inexperienced girl what it is truly like to be a wife and mother. There are certain things that cannot be adequately explained to a virgin either by words or pictures. Nor can any description I might offer here even approximate what it feels like to lose a real chunk of money that you used to own.'

I've never forgotten that. Finance is never, ever, a theoretical exercise; you're never half as detached from portfolio losses as you think you will be.

My great-grandmother taught me: Don't ever give up your ability to make your own money.

The best way to own stocks is to own an index fund.

An investor's inner time clock is crucial to getting in and getting out of markets. If the normal cock-a-doodle-doo of the rooster is at 6 a.m., there will be some investors who wake up at just past midnight -- far too early for timing a market bottom or top. And some who wake up at 10 or 11 a.m. like a college student -- far too late. Learn to recognize when your clock generally goes off, and work on getting it to ring at 6 a.m.

The best financial advice I ever got was 'Price yourself high and see what happens.' Humans aren't good at knowing their market value. When I started doing paid speaking engagements I had no idea how to price myself. A mentor told me to quote an absurdly high price. The client accepted it without hesitation and offered to pay my travel expenses as well. I no longer underprice myself.

The one thing about money that my dad always instilled in us was to just be straightforward, upfront and honest. Don't play games with people's finances. Some deals are going to happen because of that, and some deals aren't. It's a good way to conduct yourself in life in general, really; there are no downsides.

When I turned 43, I confided in one of my mentors, Judah Gribetz (former counsel to New York Gov. Hugh Carey), that I was thinking of pursuing a federal judgeship. He asked me: 'How much have you put away for your (three) daughters' college education?' I admitted it was not much.

He said, 'A judge can't be truly independent if he's always worrying about finances. Don't apply until you've saved enough to put all your kids through college for four years. And don't forget that college costs these days increase at twice the (predicted) inflation rate!'

It took me another nine years to save up to meet this goal, but when I then applied to be a federal judge, I knew I wouldn't have to worry about anything but doing the job. It was the best investment advice I ever received.

A friend said to me, Chuck, you're better off being an owner. Go out and start your own business.

Read all your statements and prospectuses closely. Don't depend on your adviser to do it for you. Everyone has the responsibility to know what they are investing in.

An investor should think like a business owner, not a renter. Most businesspeople don't get up in the morning and ask whether they should sell their business that day. If they own a pizza shop, they don't think about whether what they really should own is a shoe store instead. They show patience and persistence and try to understand their underlying business better so they can earn the greatest return for the longest period of time.

So investors are in many ways misled by stock-market volatility. The values of the underlying businesses just don't change as quickly as stock prices do. You really don't have to watch those changes hawklike day after day.