If 100k dropped in your lap for retirement, what type of account will let you put that large of a sum in it and collect interest and forget about it?
If it's Qualified Funds (Previously in a 401k or some kind of Retirement account)..i would roll it over into a Roth....or consider an Annuity. But this is all contingent on when the funds will be used or needed.
An account will not allow you to collect interest.....you will have to place it in the account (Roth, Traditional IRA, Retail Brokerage or buy into a mutual fund direct just as an example) and then allocate the funds to a particular debt instrument (Stocks, Bonds, Mutual Funds, Treasuries.....etc).
if the funds were a gift........I would split the funds in half...and throw it into something long term. I would take the 1/4 ($25,000) and put it into something more intermediate.....and trade the last $25,000.....or use it for short term investing with a little more risk. There are firms that will allow as high as 80-1 margin buying power for intraday trading (buying and selling between 930 - 4pm) ....it drops to 20-1 for overnight positions (not selling before the close of the day). So t he $25,000 can get me $2mil in purchasing power. One can make a few hundred per day with this. With over 200 trading days per year........even at $100 per day.....you are making an extra $20k per year.......which would be darn near an 80% return on the $25k alone....
it's not easy to do......but probable.
Let me explain. I watch about 30 - 40 stocks on a regular. One of my favorites is the BlackBerry maker (Research In Motion....ticker: RIMM). If you look at the price range for the day, like yesterday, the high was $100+ and the low was $97+. That's a $3 trading range. There are days when the range is between $5 - $6 per day easy....but I only look for a $1 - $2 move in price.
The stock is trading over $100 now (good earning news this morning)........so what if I buy 200 shares ($20,000) near the low...........I would like to get out after being up $1 - $2......with 200 shares.....this would get me $200 - $400 for the day not including commissions.
So for my short-term trading....I like for Volatile stocks like this with a decent trading volume. I have some stocks that are under $10......and the same logic applies...I would just buy more shares.
Hope this makes sense.