DATABASE MAINTENANCE
Premium Data maintains your US database regularly in order for
you to have an accurate record of currently trading securities.
Maintenance is performed on a daily basis.
The following actions are performed as part of daily database maintenance:
- Equity prices are adjusted for changes to a company's capital
base (such as share splits, consolidations, or capital restructures)
- De-listed securities and associated trading instruments are
moved from the main database into a "De-listed Securities"
folder (from where you may delete them at your leisure)
- Securities that have undergone a name or code change are refreshed
to reflect the new name or code.
- New securities that have been added to the database are assigned
their full names.
- Securities that have changed their exchange listing (eg. from
NASDAQ to NYSE) are automatically transferred with full trading
history intact.
WARNING: Most free sources of data do not perform any maintenance
- they simply provide flat ASCII or CSV text files each day
with no corporate action information.
Why is this important?
If you are a treating the market as a professional trader would,
you need to have an up-to-date and consistent database. You
want to spent your time analysing stocks not processing routine,
mundane corporate actions.
Can't I just use free data and do the maintenance myself?
We wish you luck if you do. We wouldn't want to do
these manually each day/week/month and highly recommend you use
a service like Premium Data to do all this hard work for you. Why
spend all your time maintaining your database when you should be
looking for trading opportunities? Here is a report of the amount
of corporate actions that we process each year:
| |
Average Maintenance
Actions Per Year |
| Exchange |
Capital Adjustments (eg splits,
consolidations) |
Company Name Change |
Symbol / Company Name Change |
Symbol / Company Name
& Exchange Change |
Delisting |
| AMEX |
18 |
114 |
30 |
30 |
84 |
| NASDAQ |
342 |
168 |
600 |
432 |
342 |
| NYSE |
210 |
492 |
66 |
96 |
96 |
| OTC |
360 |
450 |
6228 |
60 |
456 |
| TOTAL |
930 |
1224 |
6924 |
618 |
978 |
Why is it important to have OTC stocks in my database?
Many companies that temporarily fail listing rules on the other
exchanges (AMEX, NASDAQ, NYSE) often sit in the OTC-BB market until
they can rectify the issue. If you do not maintain an OTC-BB
history, when this stock subsequently relists on a major exchange
you will be without any trading history. OTC stocks are still quite
tradeable.
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