Update on my part.
I've started two new games on my PS3 and monitored the stock prices and what affects them.
- The graphs, return percentage, return value data, highest price and lowest price data for every stock on LCN is bullsh*t. They are incorrect (hell, the graph is different every time you load the friggin game) and you shouldn't pay any attention to them.
- The stock prices of each company are different from game to game (Augury Insurance in my first game was at $33, it's at $250 in my second game and $450 in the third one).
- The LCN stock exchange IS random! That means you cannot influence the stock price movement with your actions in-game. Putting it another way, the TacoBomb stocks will NOT rise even if you destroy a million CluckinBell vehicles. Same goes for FlyUS / AirEMU pair and others. Also, the stock price of Augury Insurance will not rise/drop when you destroy vehicles. So whoever posted these vids on YouTube is either a troll or got really lucky.
- The stock market refreshes every 30 (not 45) real-time seconds. When that happens, the stock prices of every company change - either moves up or down. This movement is random too - say the market refreshes and your stock X drops by $0.08. If you reload the game, it may rise/drop by a different amount. However, there are certain caps to every stock; their lowest and highest amounts.
Therefore, if you wanna get rich on the LCN SE, the best strategy I have found to work is this one:
1) Find the cheapest stock on your list*
2) Monitor that stock's movement for at least an hour real-time. Note down every single price change that happened, then note down the lowest price and the highest price this stock has reached.
3) Invest all your money when the stock is very near its lowest value. Obviously, the more money you invest, the more money you'll make when the stocks go up.
4) Save your game and monitor the price. If the stock goes up in the next refresh cycle, save your game again. If it drops, just reload.
5) Continue doing this until your stock reaches or gets close to the highest value that you noted down in point 2, then sell all your stocks.
* you'll want to invest in the cheapest stock for a very simple reason - every small movement of such a stock will grant you a bigger return than the more expensive stocks. All stock price movements in GTA V are more or less the same (rise/fall by just a couple of cents per cycle) and do not reflect the real-life stock market trading.
Example, say you invest $100k in company X which is valued at $10 and another $100k in company Y which is valued at $300. Both stocks rise by $1.50. Here's what you'd get:
$100,000 / $10 = 10,000 shares * $11.50 = $115,000 = $15,000 profit
$100,000 / $300 = 333 shares * $301.50 = $100,500 = $500 profit
Even though this method is boring as f*ck, it's the only (safe) way of making a profit on the LCN SE. So if you can, try making the most out of Lester's assassination tips so that you have at least a couple hundred million to invest for bigger returns.