Having foresight about when you plan to liquidate and reset is important for market trading. During the hours (or days) leading up to reset, a good strategy is to save up cash and wait for a product priced under its typical market valuation. Then, buy as great a volume of the product as you can (using saved cash), and when there’s an upturn in the market, reset using your inflated market cap or auto-sell the product for profits if the stock rating is unfavorable to reset at that time. This strategy is good at any point in the progression, not just before reset, but keep in mind that it’s most beneficial in the later stages when saving cash makes more sense than spending it on upgrading your production.
Another way to quickly make marginal gains in your market cap is to search the player market using the ‘Below Market Price’ & ‘Can Afford’ filter toggles. Keep in mind this does not impede your player trade quota. Holding onto these products or reselling them for a profit immediately afterward is a good way to make small jumps in the market cap with excess cash.
Produce a surplus with the intent to sell on the online market. The good idea is to produce a modest surplus in a product you are already auto-selling. This means that when the price is most favorable, and people are looking to liquidate their products rather than purchase more (at market price), you can sell your surplus on the online market at a reasonable way below the market price. People with higher auto-sell capacity or looking to reset will see this as a way to increase valuation quickly, and you will, in turn, receive a heavy bonus.
Run stop-losses on the market! For those who don’t know, stop-loss orders are orders where you automatically fill or place an order if the price falls or rises past a certain point. This is useful so that even if you aren’t online, or if you’re working on other things, you can be buying products at lows and selling at highs. In Industry Idle, this can be (somewhat) replicated by placing low price buy orders and high price sell orders. Keep in mind there will be a cap to how far you can push the limits, depending on the market price, and you need the product in stock to make a sell order.
Search through buy orders first before making a sell order; there may be a product being ordered at a higher price than you would offer. At the moment, there is no system to automatically fill your order if supply/demand prices cross over like this, but I expect it won’t happen any time soon because the way the market currently works is that the entire quantity of an order has to be filled. Having this change would result in drastic market changes.
Those are some good basic tips for trading on the markets. Still, there is a more complex strategy and specialization to be seen as you progress further in the game and expand your capabilities to trade on the market.