I was a very slow starter in 1957 with 300 dollars and I complimented that with 50% of salary for two years to get started.
I didn't have any management skills so I just put all the money in the market in 1 then 2 then 4 stocks on up to 8 stock limit.
The money management stuff never came to me as a thing to do. But i did learn that i could only manage so many streams of capital at one time. I let them grow larger and I took money out when items came up to buy.
When I got to where you are and then multiples of that, I did not change stuff. The times I could screwed up were limited by two things: not screwing up too often or immediately putting the money into a different stock. My reasoning was that there are lots of stocks and all I needed was to have stocks on hand to go into all all times.
I found out that there is a limit on what you can hold in a thread of money. I also figured out that it is important to trade with timing rather than price dominating. This means to me that I may never trade too many stocks in a block or my timing will be affected. This sounds backwards I guess. I split my streams into blocks according to what size block others trade. That means I get filled (at market) immediately.
It is a sloppy business and at my top level of shares for a given equity in a thread, I have left as much as half of what you speak of on the table on a given day. That would be a variation in performance of about +/- 7% of net profits. Mostly, I have found that I do not push getting trades done as soon in an exit as may have been possible. I trade into the peak as late as I can, across the entire peak and then I try to finish ASAP after the peak has passed.
I do not exceed holding more than 8 stocks for monitoring purposes. I cross over from one stock to another by a switch based on money velocity. As my worst held stock declines in money velocity, I then transfer the capital by selling it and then I go into the stock highest potential based upon its rising money velocity. They call this crossover trading. I enter later in the cycle than the beginning and leave earlier in the cycle than the end.
I guess what happens is that most risk is out of the picture most of the time. What I am risking mostly is how fast I am making money.
In reflection, I can now see that I probably learned my beliefs by osmosis using small amounts of capital. Having to do charts by hand in pencil for many many years as a contemprary of Darvas, sort of stamped my mind indelibly as to how price and volume worked together. When Granville came up with the P, V relation, I just addeda corrolary to complete all possibilities. When software was invented, I found, in 1957, that plotting was easier than loading punched cards into a vacuum tube speed computer. when the copire was invented, I was able to give way charts as paper prints instead of blueprints or brown lines. We traded charts then. I stored WSJ last pages for years in quarterly hanging wood bound bunches so I could back plot (6 months per sheet) new stocks for my universe. We called it back plotting to see if the stocks were reliable enough to trade for the cycles we required of them.
Divide your 500k into 8 parts. Get a universe of very high quality repeatable stocks that are cycling in rising trends. Rotate continually through the universe with your capital using the rising half cycles.
I repeat "tenured" stocks in favor of new stocks. A typical ratio of shares held goes like 10:30:70 as rotations occur. I limit my shares to a max of the lowest six figure value where the float is in the range of 5 to 30 million shares.This is typical of the compound interest formula if you divide the span into three rough sections. The hold varies. You will easily see that hold cycles are up to 8 days. They can be as short as 3 to 4 days.
I sort with EOD data and monitor on 30 min charts on qcharts.
If you do short term trading like this it takes about 20 min a day min without monitoring. If you like to monitor you can do that for 2 hours a day in the am only. I make the money I now put into equities by trading futures indexes intraday so I do monitor during the day anyway. If I were you using your capital I could use 1/5th of it to earn enough to support myself monthly in 3 to 5 days a month. Looks like you have a good prospect for the future.