"It provides an experience for all us of involved to learn about investing, trusts and markets. But it's also about benefiting other people.
"Where we give the money and how we use our capital has far-reaching, flow-on effects."
The students use profits from the fund to aid schools in Africa on a "case by case basis", through an intermediary.
Their first donation of $2000 to Ikoba Primary School in Kenya late last year gave the school a new water tank.
A second proposal was accepted by the board last week to gift $2500 to Obwororo Academy in Kenya.
"We'll be finalising that donation over the next week," Johns said.
With guidance from five adult trustees, the students had so far invested about $60,000 in shares, with the remainder in long-term deposit accounts.
The trustees had taken their time learning about how to invest and create a diversified portfolio, said Year 13 student Rommel Layco.
"We pick shares based on guidelines such as Standard and Poor's ratings, a company's dividend levels, solvency, profitability, future goals, and stability."
"Mainly we are still basing ourselves in safe secure utility companies."
Their goal was to invest about 60-70 per cent of capital in shares, with a portfolio eventually comprised of a split between secure, medium-risk and high-risk investments, Layco said.
One such high-risk investment had been in scented candle and skin-care products maker Ecoya, which had given the students their highest return yet. That offset losses made on investments in Fletcher Building.
Students had divided themselves into three groups, each responsible for either choosing the charity recipients, carrying out marketing, or handling finances.
Joshua Walker, Year 12 student and head of the marketing group, said the student trustees made most of the decisions themselves but had input from the adult trustees and a mentor.
"We do have a certain degree of leeway with our choices of investment but of course we still have some advice given."
Walker said School Aid also raised funds by running movie nights, which attracted up to 200 people and raised about $2000 at a time.
Each time the students wanted to make an investment, they pitched a proposal to the board of trustees.
Adult trustee and Economics teacher at Dilworth, Vinder Taylor, said School Aid's first few years had been challenging but was now gaining traction.
"It was a lot of work to set up. There were a lot of manuals that had to be written up to avoid pitfalls.
"They students do the research themselves, looking at journals and articles. They totally own it. We are there purely for legal reasons. We might ask a few testing questions but generally very little is said by us."
There was a certain symmetry to the students' purpose, as every Dilworth pupil is accepted to the school on a fully-paid scholarship.
"We have received a lot so it's good to give back," Layco said.
"James Dilworth gave us this education so it means something to be able to help others receive an education."
Mike Moore was also a former Director-General of the World Trade Organisation and was the current New Zealand Ambassador to the United States.
Moore's initial donation was topped up by a fundraising event held in December 2009, at which Robert F. Kennedy Jnr was the guest speaker.
