Last July -- in a very private transaction -- Dallas swinger Nelson Bunker Hunt bought $20 million worth of ancient coins. Included was a silver Athens decadrachm struck in 400 B.C. that was valued in excess of $1 million. And so, without any fanfare at all, Hunt paid a record price for a single coin roughly the size of a silver dollar and twice as thick.

All of Hunt's personal investments -- he has an ancient coin collection worth $40 million-$50 million -- should only turn out as well. Now some 10 months later, that $20 million in coins is esticontrast, there's perhaps 10 million-15 million in public collections (namely, museums and universities).

Since McNall expects inflation to continue indefinitely in double-digit territory, he looks for ancient coin prices to sustain that average 20 percent annual growth record.

Normally, the best year for these coins "is when the economy's on its ass," says McNall, who tells me NFA's '80 volume is ahead thus far about 30 percent.

The big year for ancient coins, says McNall, came in '74 -- the last big recession year, many mated to have risen nearly 20 percent or roughly $4 million. In that investment, at least, Hunt has managed to keep one step ahead of inflation.

The middle man in that $20 million coin transaction is one of the more intriguing entrepreneurs I've met. He's Bruce McNall, the roly-poly 30-year-old president of Numismatic Fine Arts Inc. Based in Beverly Hills, Calif., NFA is the nation's largest dealer in ancient coins (at least 1,500 years old); its annual sales run about $25 million.

Now I know from beans about ancient coins (which are primarily from Greece and Rome), but it's a darn shame I didn't learn about them earlier. McNall, who began collecting them at the age of 12, tells me they've been increasing in value at an average rate of about 20 percent a year over the past dozen years. This is in contrast to the roughly 13 percent rate of growth all coins achieved in the same 12-year period.

Normally, explains McNall, you never have a big increase -- or a big loss -- in ancient coins over a short period of time. These are not designed for overnight killings.

"We're an alternative for people who want to hedge against inflation," says McNall. And if inflation weakens, you'll still be protected, he tells me, if you'll hold the coin for at least a year "I've sold over several hundred thousand ancient coins and I don't know of a single instance where any of them has ever gone down in value."

A big plus; as he sees it the law of supply and demand. McNall estimates that there are only about a million ancient coins in dealers' hands and private collections throughout the world, in coins practically doubled in value in that year alone.

It should be pointed out that '74 was also the year in which one of the world's most important coin collections was put up for sale. That was the $10 million collection of the Gilet family of Paris (the founders of the Gillette Co.) and it created international excitement in coin collecting.

Interestingly, it was at that very auction that McNall broke all records for the purchase of a single coin when he paid $420,000 for the same Athens decadrachm that Hunt later acquired for over $1 million. Shortly after McNall bought the coin -- there are only seven known to be in existence -- he sold it to a Los Angeles collector at about a 5 percent profit.

McNall, whose clients include such leading business figures as Norton Simon and Occidental Petroleum boss Armand Hammer, says if a person buys intelligently and focuses on coins in good condition and with some rarity to them, "the downside risk is practically nil."

McNall, whose average coin sells at a few thousand dollars (although they start as low as $10), admits that liquidity -- the ability to sell at close to current value -- isn't as good as in the stock market. But the liquidity, he insists, is better than it is in real estate. He further points out that coin auctions are going on all the time and a collector can always place a reserve -- or a minimum price -- on what a coin can be sold for.

To avoid getting ripped off, McNall strongly suggests that buyers make their purchases from dealers associated with the International Association of Professional Numismatists.