The HAGI classic car index rose to an all time high in April.
The index covers vehicles from the pre-war era to the present day, providing a bellwether for the health of the market.
It exceeded its trading range for the first time since September 2014, indicating that momentum is returning to the sector after three slow months at the start of the year.
This bodes well for collectors, as it suggests the substantial sums paid at auction in recent years are becoming increasingly normalised.
However, HAGI warns it has become increasingly difficult to source classic cars at good prices - a factor that could cause turbulence further down the road.
Among the marques, Porsche showed particularly strong performance last month. It advanced 6.6%, slightly higher than Ferrari, which gained 6% from March.
As for the year to date, Ferrari leads with 7.1% growth against 6.6% for Porsche.
While a number of major sales have taken place at the big auction houses, including the recent RM Sotheby's sale of the Andrews collection, collectors still have the key summer and winter sales to look forward to.
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