Mining The Web by Neville Millar
Yes, Data Matters
Mining The Web
Can we really use something that’s already available on
our computers to get the data we want to help us in our
trading? Find out here.
It may have its limitations, but Microsoft’s popular
spreadsheet program Excel can be used to do everything
from archiving historical financial data, to
tracking technical indicators, to maintaining options
valuation/volatility models. Oftentimes, you use cell formula
scripting to create Excel utilities involving mathematical
computation. An alternative to cell formula scripting is the
Excel Visual Basic for Applications (VBA) programming
engine, which can be used to build software programs that do everything from processing advanced analytical tools or
trading system models to data mining the Internet.
It can be done
VBA programming code is easier to understand than advanced
cell formula scripting, and Excel provides an easy-to-learn
programming environment. The built-in macro recorder is an
excellent set of training wheels for the beginner, showing you
how various Excel tasks translate into programming code.
Learning VBA at your own pace also gives you the opportunity
to discover different ways to build market-timing indicators
and fundamental analysis tools that are in line with your trading/
investment decision-making temperament.
My objective in this article is to show you how Microsoft
Excel VBA can help speed up the process of downloading data from financial websites. Manually transcribing data from
web pages can be tedious, and Excel workbook downloads
available on popular financial websites such as Yahoo.com
and NASDAQ.com are formatted in the inverse order of
the standard database architecture. The most current record
should be at the bottom of the list instead of at the top. With
the help of VBA, Excel programs can combine multiple subroutines
(referred to as “macros”) to reverse the date order
and set the correct display format. After you have finalized
your historical data redesign, you can autodownload
a daily basis from the Internet in a fraction of the time it takes
to do manual updates.