Logs that can't be edited later
Posted: Fri Oct 30, 2026 12:55 pm
Logs that can't be edited later
A trade log kept in a spreadsheet can be changed after the fact. That's convenient and a bit dangerous. Memory is flexible, and a log tweaked to be tidy loses its value as evidence.
For serious analysis, or for disputes with a broker, a tamper-evident record helps. The simplest approach is exporting platform history on a fixed schedule, saving it with the date in the filename, and never editing the originals.
A step up is computing a hash of each file, a short fingerprint that changes if a single character is altered, and storing the hashes separately, such as in an email to oneself. Any later change would be detectable.
Timestamps matter too. Logs written by scripts should record the time from a synchronized clock, along with the source of that time.
The point isn't paranoia. It's discipline. A record that can't be changed makes the trader honest with themselves, since the numbers stay as they were, flattering or not.
When a dispute with a broker arises, a clean chain of unedited exports is much more persuasive than a spreadsheet with unknown history.
There's a cheap way to get most of this benefit without any scripting. Export the history report every Friday, save it with the date in the name, and email it to a separate address. The mail server's timestamp is an independent record that the file existed on that date, with that content.
For script-generated logs, writing each line with a running sequence number makes deletions detectable, since a missing number stands out. Combined with periodic hashes, the log becomes difficult to alter without leaving traces, and that's enough for most disputes and for honest self-assessment.
What keeps trading records from being quietly changed after the fact?
A trade log kept in a spreadsheet can be changed after the fact. That's convenient and a bit dangerous. Memory is flexible, and a log tweaked to be tidy loses its value as evidence.
For serious analysis, or for disputes with a broker, a tamper-evident record helps. The simplest approach is exporting platform history on a fixed schedule, saving it with the date in the filename, and never editing the originals.
A step up is computing a hash of each file, a short fingerprint that changes if a single character is altered, and storing the hashes separately, such as in an email to oneself. Any later change would be detectable.
Timestamps matter too. Logs written by scripts should record the time from a synchronized clock, along with the source of that time.
The point isn't paranoia. It's discipline. A record that can't be changed makes the trader honest with themselves, since the numbers stay as they were, flattering or not.
When a dispute with a broker arises, a clean chain of unedited exports is much more persuasive than a spreadsheet with unknown history.
There's a cheap way to get most of this benefit without any scripting. Export the history report every Friday, save it with the date in the name, and email it to a separate address. The mail server's timestamp is an independent record that the file existed on that date, with that content.
For script-generated logs, writing each line with a running sequence number makes deletions detectable, since a missing number stands out. Combined with periodic hashes, the log becomes difficult to alter without leaving traces, and that's enough for most disputes and for honest self-assessment.
What keeps trading records from being quietly changed after the fact?