STVF is a VERY RISKY investment! They are a development stage company with zero revenue so far. Just take a look at what was said in their latest S-1 SEC filing from 1/30/13:
Risks Related to this Offering
We must raise additional capital in order to continue operating our business, and such additional funds may not be available on acceptable terms or at all.
We are a development-stage company and if our development efforts fail you could lose some or all of your investment.
We are in the development stage. We have not conducted any significant operations to date or received any operating revenues. Potential investors should be aware of the problems, delays, expenses and difficulties encountered by an enterprise in our stage of development, many of which may be beyond our control. These include, but are not limited to, problems relating to research and development of stevia seeds, seedlings, and leaf supplies, obtaining sufficient acreage to successfully cultivate and harvest stevia, product testing, branding, sales and marketing, and costs and expenses that may exceed current estimates. We may not successfully develop and commercialize or sell our potential stevia products, and any products we do develop may not be accepted by the marketplace. We may never realize any revenues, and if we do, our revenues may not be sufficient to support our operations and future research and development programs. As a result, you could lose your entire investment.
We are not currently profitable and may never become profitable.
We expect to incur substantial losses for the near future, and we may never achieve or maintain profitability. Even if we succeed in commercializing stevia products, we could still incur losses for the foreseeable future and may never become profitable. We also expect to experience negative cash flow for the foreseeable future as we fund our operations and make significant capital expenditures. As a result, we will need to generate significant revenues in order to achieve and maintain profitability. We may not be able to generate these revenues or achieve profitability. Our failure to achieve or maintain profitability could negatively impact the value of our common stock and you could lose some or all of your investment.
These financial statements have been prepared on a going concern basis, which assumes the Company will be able to realize its assets and discharge its liabilities in the normal course of business for the foreseeable future. The Company has incurred losses since inception resulting in an accumulated deficit of $2,616,792 as at September 30, 2012, and further losses are anticipated in the development of its business, raising substantial doubt about the Company's ability to continue as a going concern. The condensed financial statements do not include any adjustments that might be necessary should the Company be unable to continue as a going concern.
I encourage you to go read the full report on the SEC website.