I lost 30K once while I slept, because of a computer glitch and a hinkey power outlet.
Top that babypipsters.
Jay
Can’t top that Jay, but painful lessons nonetheless…yes…been there too…lol. Mine was the loss of confidence in my trading plan right after I started live. After the first 2 years I thought I had it all figured out. Of course my plan didn’t really include a stop loss, and just before going live, my demo account tanked from $5k to 1 in one bad trade that just didn’t come back. So when I went live, that possibility freaked me out anytime the drawdown in my trades got to my “mental” stop area and all I could see was it getting worse like that last demo trade so I’d close it early at a loss, and then see it go back in my favor. Then it seemed my whole plan just fell apart when I put in a stop because it hadn’t been part of my plan before. So, I lost half my deposit before stepping back to demo to figure out the stop loss part…that was 2 years ago. Good news is, after learning, trying out and discarding several new methods, which takes awhile to do when forward testing and on top of that, only part time, my latest demo of 100 trades (with stops) seems to suggest it may be time to try again…right after New Years 
I’m looking forward to the New Year, as should all other traders who are thinking about taking the next step up to a live account, or even live traders that are looking at trying out new adaptable trading approaches. I guess the market conditions, from a day traders point of view such as myself, is that this is the new ‘normal’ day to day movement typically seen. Of course there are going to be exceptions to this, so don’t pick me up on that!!
My biggest lesson, which has now been learned, is when it comes to back-testing. I’m talking about testing over historical data the long and dull way…you know, day by day, month by month, year by year. No EA is being used, it’s you doing the grafting. I always use to say to myself “of course I would have bought/sold here, its obvious that price was going to respond that way after opening”. In short, we ALL trade from the far right hand side of the chart, so being HONEST to your self is well worth learning.
There is some advantages to back-testing this way, sure you clock up thousands of screen hours, I demo back-tested for over two years. Each and every day I would spend at least two hours doing this. I suppose when you start to get what look like good results it then motivates you to continue doing more. Almost as if the hard work is finally paying off, no?
I wont continue stating what we “Experienced Traders” already know, apart from the fact that personal honesty is key. You will soon realise when you open a live account that your a big fat liar if you start loosing money much faster than you originally anticipated.
James
Glad to hear sweet
might i inquire if said plan includes anything with supply/demand daily zones?
Jay
Yes it does Jay 
Pffffffffffft…
Like those matter.
Any really good trader knows it’s all about indicators.
As a newbie I learn’t this - don’t allow computer updates either - i was in the process of putting in SL and decided to ‘install updates’. My PC decided to have a slow moment then 10 minutes later the price had moved 100 pips against me! Oh also going out and working on your golf swing won’t bring the market back in your favour either.
Heres a lesson from last night. Doing anything related to trading while drinking alcohol. I actually dont drink that much nor have had access to mobile trading, its actually not something i ever considered being in that situation. But no excuses it was a Seriously HUGE mistake, no I didn’t lose money, nor entered new trades. But that’s not the point. Maybe it would have been better if i did take a loss. the point is looking back i know how f-ing DANGEROUS that was. Basically playing with my life blood, you know your capital while basically with the mind of a 8 year old. This is something that’s going into my Sacred Mistakes and Lessons learned list.
I can totally relate
I can relate to forgetting about unused entry orders. With my first live account, that I blew in 3 months, I forgot about some entry order that triggered while I was asleep. When I woke up it had actually gone in my favor and that was the best trade I had with that account!
In total i blew three accounts, the last two i was doing carry trade but overleveraged, today sometimes i do carry trade but with ever 100 USD invested i open a position with just 0.01 micro lots.
Regards.
Figuring out your SL and TP before you execute an order. Too many times I’d enter a scalp when a trendline broke without a clear idea on where to exit. 
Ahhh…
This is an easy one. Just look at any posts of mine prior to, say, 2009!!! LOL!!!
Regards,
Dale.
Double check all your work before you submit an order, especially if your broker takes weekend orders/trades. Man have i put in limit orders incorrectly and had them become marketable. Having to eat a 10 pip spread or more sucks really really bad.
NOT reviewing all of my losing trades - a mistake I still on occassion make to this day, i’m a bit embarrased to say.
At least I can say, on the level, I review the vast majority of losing trades.
Most don’t even realize this is a mistake they are making. Trust me, it’s possibly the biggest of all.
And, if your still not profitable yet? Yea… this mistake should be near the top of your list too.
Jay
Mistakes. I made them too. Albeit not in a fashion to blow accounts. Closed one in profit and working now on the second one.
I did learn from others. Reading. It’s all there in the net for free. Listen to those who are not too euphoric. Well, then also think. There is not such a thing as thinking too much. You can only think too less. Don’t just believe in anything you read, but think about it. 95% of what one can read is utter nonsense, so it’s your job to filter out the nonsense and go with what is good information.
Mistakes belong to everything you do and sometimes it generates pain. That’s not different in trading. Anyways, don’t let a small mistake become a huge one! Always use a stop loss and calculated risk! You may lose some equity of your account, but only what you risk on that trade and not your whole account. After a few days you will be thankful for that small loss.
Oh and yes, I can suggest (back)testing as well. Without any testing for less than ~ 2 years and 100 trades one trades more or less based on hunches and luck. And even with those tests it doesn’t say you have a warranty for success. You just know then what your edge is and your max. risk. Which sets you apart from most of the losers who have no stop, no risk/money management and no clue, anyways.
Chasing the last few cents to a round number is a killer!
“its only a pip how hard can it be!!!”
When taking a big psychological hit, its very necessary to sit out and decongest, even if you dont think you need it yourself. Thanks to all the people that made me take a break
Yes. This mistake, above all others, has single handedly cost me the most…more than all the rest, both in terms of time AND money.
If I hadn’t gotten lucky and heard the right message on the right day and decided then and there to just STOP TRADING for a solid 6 weeks, I was on my way to losing about 100K when all would have been said and done.
I haven’t made it this mistake in quite a while, and have rules now to prevent me from doing such again at least to anything that would really hurt me. but man, lets just say one COULD lose everything, regardless of what they have, if this is not kept in check.
Most dangerous thing of all IMO to a experienced trader.
Jay
P.S. Where’s my $1 man!