What is the rationale behind the allocation you chose for me?

Here is how the blooom algorithm works (at a high level): We research and classify each of the fund options within your plan into one of about 14 different categories (things like large cap, mid cap, international, emerging mkts, etc). Once each of the funds is in its ‘asset class bucket’ our investment algorithm optimizes for funds that meet your target allocation while maintaining the lowest internal expense ratio

Here is the order of importance within our methodology:

Get the stock-to-bond ratio appropriate for your timeframe to retirement.
Get you exposed to all appropriate asset classes available within your 401k fund lineup.
Select the lowest cost funds for each asset class.