<prompt> Human: My dad wants to grow his 401k more than the 1-6 he has been getting per year. We have some stocks picked out but want to know if it is even possible for him to do this without taking a penalty on his 401kEdit: Did not mean ALL of his 401k into 1-3 stocks just like 10-20 of it into those stocks my bad for not clarifying that.  <response>: the plan has a set array of funds available because it has to pay to make them available. the only way he can invest in something not held in the plan is to not be in the plan. OCCASIONALLY you will have a self directed account option on an employer sponsored plan, but even then they typically limit you to mutual funds all be it hundreds of them to choose from so he would likely not be able to invest in stocks even in this scenario.on a side note, putting his entire retirement savings into 1-3 stocks is an idiotic idea. 