Aqui vai uma ajuda sobre alterações de tickers que tinha aqui arquivado:

Why did my stock's ticker symbol change?

When a ticker symbol changes it's usually not a good sign. Tickers of publicly traded companies generally only change for one of four reasons:

   1. The company has merged with another company.
   2. The company had a name change.
   3. The company has been delisted (indicated by symbols such as .PK, .OB or .OTCBB).
   4. The company has filed financial statements late or even gone bankrupt.

You may have also noticed that Nasdaq-listed securities have four or five characters. In this case, the fifth character often communicates a piece of information, and it can also mean something is wrong with the company. For example, if a "Q" has been added, this means that a company is in bankruptcy proceedings, and "E" means the company is late on its SEC filings. Below is a complete list of fifth symbols on the Nasdaq and what they mean:

A - Class A
B - Class B
C - Issuer qualifications exceptions
D - New
E - Delinquent in required filings with the SEC
F - Foreign
G - First convertible bond
H - Second convertible bond
I - Third convertible bond
J - Voting
K - Nonvoting
L - Miscellaneous situations, such as depositary receipts, stubs, additional warrants and units
M - Fourth class of preferred shares
N - Third class preferred of preferred shares
O - Second class preferred of preferred shares
P - First class preferred of preferred shares
Q - Bankruptcy proceedings
R - Rights
S - Shares of beneficial interest
T - With warrants or with rights
U - Units
V – When issued and when distributed
W - Warrants
X - Mutual Fund
Y - ADR (American Depositary Receipt)
Z - Miscellaneous situations, such as depositary receipts, stubs, additional warrants and units