The Metastock import preferences panel, first help recognizing existing stock to be updated. There are ambiguous situations. By default, Mastock has a lenient approach; for instance if a stock has the right code, even though the name might have changed, then it’s the same stock. All of the assertions above are generally true, and you should not have to change them but, you can if you want a different strategy.
Replace existing quotes: This might be what you want when importing a directory, but you can chose to just address the missing days... the time to import is significantly longer when replacing existing quotes.
Ignore Time Gaps is the setting by default. It simply means, before importing, Mastock will check existing data first and last date, and will assume all data before those two extremes are valid. If not, Mastock, during the import operation will verify if there was a time gap in current data, and fill those gaps... The time to import is, however, considerably longer.
For the two settings above, the difference in time can be very significant. Not a big deal for a few stocks or many stocks over a short period of time but, as a reference, importing 1500 stocks daily data over 10 years, might take 20 min or several hours depending of those.
Volume multiplier is to help align data between providers. Metastock data usually come from Reuters, and data for volumes are actuals divided by 100. On the other hand, data imported from Yahoo, for instance, are undivided data. The default of 100 is generally right, don’t change it unless you see discrepancies between imported and downloaded data.
The portfolio indicates the name of the portfolio where imported stock will be regrouped.