Fund managers and analysts from more than 100 institutions have been invited to the Barbican, where they can browse among stands staffed by senior management of businesses as diverse as JLI Group, which produces much of the popcorn eaten in British cinemas, and TGI, which makes the speakers found in most of Ford's European cars.
Apart from promoting Hoare Govett's position as a leading player in the smaller companies sector, the show is designed to allow investors the chance to identify far more potential investment opportunities than they could in the space of a normal working day.
For the companies, the exhibition provides a shop window where they can try to sell their wares to a significant proportion of the investment community.
The average market capitalisation of the companies exhibiting is pounds 40- pounds 50m, just the range into which JLI falls.
Its chief executive, Yoav Gottesman, said: 'The benefits of taking part are both tangible and intangible.
'It's a useful forum for the company to meet a large number of institutional investors. In the normal course of events you don't get to see so many people
from the investment community at one time.
'I hope it gives them a small insight into the smaller companies scene at the moment, especially after the difficult times the sector has been through.'
Frederick Cooper, the metal finishings and architectural hardware group, is a first-time exhibitor.
Its chairman, Eddie Kirk, said he went to the trouble of engineering the timetable for a new US acquisition so that he would have a good story to tell at the exhibition.
'Sometimes, it's not easy to persuade institutions to see smaller companies such as ours,' he explained.
'Although we already have a reasonable list of institutional shareholders, it gives us a chance to persuade new people to talk to us.'
By the same token, fund managers appear to like the opportunity to see so many smaller companies at once.
John Alexander, at Henderson, said: 'It really is an interesting selection of companies.
'Of the 45 companies exhibiting, I already hold 19 of the shares, but I would hope to identify a couple more. Indeed, I already have two or three on the list underlined. It will also be interesting at this point to talk to companies and get a feel for whether the recovery is for real this time.'
Hoare Govett certainly believes that its policy of sticking with the sector through a rough recession is beginning to pay off. Its fund management arm launched its second smaller companies investment trust last week, aiming to pick up pounds 25m-pounds 50m.
Pat O'Bryan, of Hoare's smaller companies team, said: 'When we held the last exhibition in September 1991, we thought the recession was coming to an end then. This time, I think we can be more confident that the worst is behind us and that smaller companies are once again coming into their own as investment opportunities.'