cleaning up undesirable ticks (if you see a foul tick you could possibly check out forcing backfill in hope that data seller has cleaned up its database and you may get fixed data - will work perfectly for eSignal that basically seems to repair bad ticks after they materialize) https://amibroker-data-feed31852.anchor-blog.com/8268355/data-for-amibroker-no-further-a-mystery