Remember when the world first laid eyes on Daniel Radcliffe, Emma Watson, and Rupert Grint in 2001's "Harry Potter and the Philosopher's Stone?"

These plucky young thespians were cute, cuddly and in desperate need of a reassuring hug as they manoeuvred their way around Hogwarts School of Witchcraft and Wizardry.

These fledgling British actors were also unknown to Hollywood. That has all changed thanks to "Philosopher Stone's" blockbuster success.

J.K. Rowling's opening tale in her seven-part series earned US$974.7 million around the world, with fans rushing to experience Chris Columbus' faithful rendering of this story about an ordinary boy who learns that he is a famous wizard.

Since that auspicious start to the Warner Bros. franchise, the Potter films have made US$5.4 billion around the world. That figure is destined to grow once Parts 1 and 2 of "Harry Potter and the Deathly Hallows" bring Rowling's boy wizard saga to an end.

But without that elusive screen magic generated by Radcliffe, Watson, and Grint, one wonders if this franchise would have failed faster than one of Ron Weasley's spells.

Standing now on the brink of life beyond Harry, the future ahead raises some big questions about these stars' bankability, especially as they transition into adult roles.

Will Radcliffe, 21, ever find a role that eclipses Harry Potter? Can 20-year-old Watson ever be perceived as a sexy starlet after playing the bookworm Hermione Granger?

And as Grint, 22, becomes more of a man of action in "Deathly Hallows: Part 1," one wonders if he could have a career that leaves Watson and Radcliffe in the dust?

If money alone were Hollywood's chief measure of success, these stars would be counted among young Hollywood's elite.

In 2010 Radcliffe ranked No. 82 on Forbes' Celebrity 100 List. His salary for 2010 was US$25 million.

In October of 2010 The Economic Times reported that Radcliffe's net worth had doubled in the past year. Radcliffe's personal fortune reached US$45 million, making him richer than Prince William and Prince Harry. The grandsons of Queen Elizabeth II are each worth US$44 million.

Watson and Grint have also cashed in thanks to their Potter fame.

Watson's current net worth has grown to US$32 million.

In 2007, Forbes estimated that Grint earned US$4 million a year. That placed Grint at No. 16 in Forbes' list of top 20 earners under 25.

Yet money alone cannot assure a smooth transition from child star to grown-up headliner. Just ask Lindsay Lohan.

Potter whiz-kids no more

Financial freedom certainly give these stars the luxury of choice.

Watson, for example, jumped at the chance to co-star with Kenneth Branagh and Michelle Williams in the 2011 drama, "My Week With Marilyn." But the actress also dove into a liberal arts course at Rhode Island's Brown University in 2009.

In 2009 Watson signed a modelling contract with Burberry, the luxury British fashion house, Burberry. She also began her involvement as a creative advisor for People Tree, a fair-trade clothing brand.

Such varied choices show spirit. But that cannot safeguard these stars from Hollywood typecasting.

No one has grasped that reality more than Radcliffe.

The actor made big news in 2007 when he appeared in the nude as stable boy Alan Strang in the London revival of Peter Shaffer's play, "Equus."

Radcliffe's involvement generated huge media interest, and advance sales that topped £2 million in England. His surprisingly nuanced performance also earned good reviews, both in London and on Broadway, where the production moved in 2007.

Radcliffe flexed new acting muscle in the modest 2007 film "December Boys." That new maturity landed Radcliffe plum roles in the 2011 thriller "The Woman in Black" and 2011 action-drama "The Journey is the Destination.

Some even speculate that Radcliffe will direct his first film in the next few years.

As for Grint, thisPotter star may face the biggest battle of all to transcend his clueless alter ego, Ron Weasley.

Work in small flicks like the 2006 comedy "Driving Lessons" and 2009's  gritty  teen drama "Cherry Bomb" are slowly establishing Grint's range as an actor. Whether that will lead to "leading man" roles in Hollywood remains to be seen.

At the very least, Grint, Watson and Radcliffe have shown they are not willing to rest on their Potter laurels. With a little bit of magic, the future could be even brighter than Harry Potter imagined.