Public media and previous research have focused mainly on listing day returns of initial public offers (IPOs) by new economy companies in specific periods such as before April 2000, without examining any subsequent equity offers by new economy companies. This study addresses the issue of multiple equity offers and provides additional understanding of new economy initial and seasoned equity offers (SEOs). Without, a priori, favouring any existing explanation of initial and long-term share returns, this research tests a wide range of theories in order to provide insight into share returns of equity offerings by new economy companies listed on the Australian Stock Exchange between 1994 and 2004. In general, this thesis documents the ability of publicly available information (obtained from offer documents and company announcements to the market) to explain the returns of equity-issuing new economy companies in Australia. In other words, how useful is public information in the valuation of initial and seasoned equity offers of new economy stocks? Specifically, the thesis seeks to examine the ability of public information to explain (a) listing day and long-term returns subsequent to initial public offers by new economy companies, and the probability of IPO withdrawal, (b) announcement period and long-term returns of seasoned equity offers by new economy companies, and (c) the relationships between the initial and any subsequent equity offers by new economy companies (within three years of listing) in terms of probability of seasoned equity offer, duration between the IPO and the first SEO, and frequency of seasoned equity offers within the first three years of IPO. First, the thesis finds that public information is used by investors to value new economy stocks on listing day and in the long run. The negative effect of withdrawal probability on listing day returns of successful IPOs is confirmed in this thesis in the context of the fixed-price offer process in the new economy sector in Australia. While new economy equity-issuing companies have inferior long-term returns compared to the market index and the small capitalisation stock index, they do not underperform relative to their respective industry index returns. Second, this study also finds that public information can explain new economy stock returns around the announcements of seasoned offers and in the long run. Third, the results reveal that publicly available information can be used to explain the incidence and to estimate the probability of seasoned equity offers by recent new economy IPOs. Furthermore, it is found that public information has the ability to explain the duration between the IPO and the first seasoned offer, as well as the frequency of seasoned offers in the first three years after listing. The results of the study support the theoretical predictions about the effects of public information (representing IPO characteristics) and the incidence of a seasoned equity offer. In particular, IPO quality signalling by retained ownership and by underpricing, and the market feedback effect of post-IPO returns have been confirmed for new economy equity offers in Australia. Underpriced new economy IPOs and those with greater proportion of ownership retained after the offer are significantly more likely to have a seasoned equity offer within three years of listing. Likewise, new economy IPOs with superior aftermarket returns are significantly more likely to have a seasoned equity offer. The implication of this research is that public information contained in offer documents and in company announcements is important to valuation of the Australian Stock Exchange listed new economy companies. Thus, the regulators and the Stock Exchange should continue to insist on a high level of information disclosure prior to equity offers in order to enable investors to properly value companies within the new economy sector.