If you have been an ardent Lego collector since the turn of the century, hold on to those sets. They might be even more precious than gold - literally.
An analysis conducted by British daily The Telegraph has revealed that the popular toy could potentially net owners a far superior return than if they invested in the stock market or in gold.
Since 2000, Lego sets kept in mint condition - so long as they are still in their original boxes - have increased 12 per cent in value each year.
Certain sets which cost less than £100 (S$208) are now selling for thousands on the reseller's market, said the paper.
In contrast, investors who bought gold received an annual increase of 9.6 per cent in value over the same period, while the FTSE100 (an index if 100 companies on the London Stock Exchange) had an average annual return of 4.1 per cent since February 2000.
In particularly high demand are Lego sets from the cult Star Wars film franchise, although Ed Maciorowski, the founder of Lego investing website BrickPicker.com, said top dollar could only be guaranteed for sets which had never be opened.
Used sets, while less valuable, could still be worth hundreds of pounds more than their original price.
"The neat thing is that all sets are retired at some point, and several hundred are retired each year a movie run ends, a licence expires or the Lego company wants to refresh its range," he told The Telegraph.
"That means anyone with a set at home - large or small, it doesn't matter - could have quite an investment on their hands if it's in good condition, as this stuff appreciates very well in value."
For instance, the Ultimate Collector's Millennium Falcon - the iconic spaceship piloted by Star Wars character Han Solo - now retails for £2,712 compared to its retail price of £342.49 when it was first released in 2007.
Two other Star wars Lego sets - the Death Star II (2005) and Imperial Star Destroyer (2002) - also made it into the top five of the list of most expensive Lego sets on Brickpicker.com.
The most recent Star Wars film, The Force Awakens, is expected to drive further demand.
Meanwhile, the set that has experienced the biggest jump in value - a return of 2,230 per cent - is the model of a hotel first released in 2007. "Cafe Corner" originally retailed for £89.99 but is now worth £2,096.