Overview
Form S-1 is a the most basic form filed to register securities, for which no other form is authorized. This form is most typically seen filed in initial public offerings (IPOs).

Form Uses
This form is used to gain financial and other material information about a company that is issuing securities. The most common use for this form is in initial public offerings, where it can offer insight into a company's valuation and business operations.

Reading the Form
There are three major portions of the S-1 form:

1. Letter to Shareholders from Parent Company - This can give you a nice history of the parent company, their reason for the spin-off, and and other relevent information.
2. Information Statement - This section contains all the information investors need to know. Occasionally, portions of this section will be left blank and amended (with S-1/A filings) at a later time.
3. Financial Information - This section contains all the financial information, including pro-forma statements. These statements show what the financials would look like if the spun-off division were its own company in the past.

Overview
Form 10-12B is a form filed to register securities pursuant to Section 12(b) of the 1934 Act.

Form Uses
This form is one of the most useful of the security registration forms because it relates to securities created as a result of a spin-off. Spin-offs are great opportunities for investors because they have been shown to outperform the overall market in their first year of existance. This is commonly attributed to the fact that most parent company shareholders are uninterested in spin-off securities and sell them immediately. This leads to a fundamentally unjustified decrease in the stock's price, which creates a great buying opportunity for the enterprising investor.

Reading the Form
There are three major portions of the 10-12B form:

1. Letter to Shareholders from Parent Company - This can give you a nice history of the parent company, their reason for the spin-off, and and other relevent information.
2. Information Statement - This section contains all the information investors need to know. Occasionally, portions of this section will be left blank and amended (with 10-12B/A filings) at a later time.
3. Financial Information - This section contains all the financial information, including pro-forma statements. These statements show what the financials would look like if the spun-off division were its own company in the past.