Can a Business LLC own stocks?
An LLC taxed as a "C" Corporation gets preferential treatment and a lower tax rate on the first $50K of income at 15%, and then 25% the next $25K. Additionally, if the company invests in dividend paying stocks, the company gets what is known as a Dividend Received Deduction, or DRD, where they can write off 70%-80% of the dividend completely. So, to the extent you are going to own dividend paying stocks, there can be a benefit and you can accumulate funds inside your LLC to let it compound. The trick is getting it out of the corporation later to you with the least amount of tax.
One note though, as you accumulate monies inside the LLC though, make sure the monies are "appropriated" for some (possible) future use, whether you actually do or not is okay. It just needs to be earmarked and documented for something like expansion, new building, etc. This is can be easily done with corporate minutes. You just don't want "unappropriated," retained earnings inside the company over $250K, or $150K if Professional LLC, as they will deem you a holding company and add a penalty tax of 30%. This is a complicated question and you need to seek someone with a strong accounting background in this area for advice. This is not your typical financial planner question, but dives into numerous tax law questions. And more often than not, the trouble and hassle isn't worth the tax savings for just the difference in tax rates. It can be worth it if you consistently and continuously do it so the compounding takes effect. One last thing, if you have no or very few employees, you should consider a retirement plan. There are some that will allow you to make very large contributions if you are trying to shelter large amounts of income. Best of luck!
An LLC can own stocks, but all income generated from the LLC is passed through to the owner's personal tax return. So if the question is, "Should I setup an LLC to for the purpose of purchasing stocks," the answer is no because there is no benefit to this as there are expenses associated with establishing and maintaining a corporation. However, if you already have an LLC and have excess cash that you wish to invest, and not withdraw for whatever reason, you can certainly open an investment account for the LLC and purchase securities of any type.