Sri Lanka's Securities and Exchange Commission is holding the fair in Colombo with stock brokers, the Colombo Stock Exchange, fund managers and other market intermediaries having stalls.
SEC chairman Nalaka Godahewa said the market has gained about 30 percent in the past few months.
The target was to increase market capitalization to 20 billion US dollars to 50 billion by the time Sri Lanka's gross domestic product was expected to hit 100 billion dollars in 2015, he said.
He said already a 10 point plan spearheaded by the SEC was having its effect.
Godahewa said the SEC was going beyond its 'traditional role' of regulating to actively develop the market.
"To regulate first there has to be a market," he said.
Economic development minister Basil Rajapaksa said higher agricultural prices was putting more income in the hands of farmers and he hoped they would end being invested in long term projects through the stock market.
Rajapaksa said in places as far as Embilipitiya people were now buying stocks. People ranging from pensioners to small farmers and entrepreneurs were buying stocks.
He said the SEC was taking steps to protect investors but special care must be taken with small investors.
When markets collapse many investors who loose will not only bring disrepute to the stock market but also hurt the entire economy, he said. There were such examples in other countries, he said.
Minister Rajapaksa said soon after he made a similar speech at the investor day seminar last year most of the SEC top officials had resigned.
He hoped such an event would not be repeated. It was important for institutions to have continuation to have stability, he said.
Central Bank Governor Nivard Cabraal said there was close co-operation between the Central Bank and SEC to develop capital markets and boost saving and investments to achieve higher growth and lower poverty.
In recent growth has averaged 7.5 percent compared to about 4.5 percent after independence, he said.
Per person economic output had risen fast and unemployment was falling, and more savings and investments will help generate faster growth and lower poverty.
SEC investor day aims to create an informed investor public. The event has several workshops in Sinhalese, Tamil and English. SEC launched the second print of an investment guide at the event.
IIFL Securities Ceylon launched a book '108 Mantras for Financial Success' also in all three languages at the investor day.