401(k) providers · October 2026 Edition
Fidelity Investments vs Vanguard
Four of fourteen models named Fidelity Investments first on the direct prompt; zero named Vanguard. Fidelity Investments was named by nine of the fourteen models and Vanguard by fourteen and Fidelity Investments carries 23 labels and Vanguard 46, so the shares are not directly comparable.
Named in one category this edition.
Named in three categories this edition.
First-choice share13%5%Of first choices across the direct, paraphrase, budget and scale prompts, 0 to 100.
Negative rate4%4%Negative labels as a share of the product's labels, 0 to 100.
Rank in category#4#7A position in a field of 12; printed, not drawn.
Labels2346A count; the two differ.
The two percentage rows are drawn on one 0 to 100 track, Fidelity Investments reading right to left. Rank and label count are printed, not drawn.ADP Retirement Services was named alongside these two in nine of the fourteen direct answers. Human Interest vs Fidelity Investments · Human Interest vs Vanguard · Guideline vs Fidelity Investments
Share is the count of first choices across the direct, paraphrase, budget and scale prompts over all fourteen models, for a mid-market B2B company; rank is within the category; every quote names the model and the prompt it came from. Both figures come from the 401(k) providers page.
By framing
How many of the fourteen models made each the first choice, per way of asking, and how many argued against it.
Fidelity InvestmentsFirst choices, of fourteen modelsVanguard
Direct40
Paraphrase31
Comparative31
Budget-constrained02
Scale-constrained00
Negative141 against Fidelity Investments · 2 against Vanguard
Bars are first choices, 0 to 14 each sideModels that argued againstA model can name both, so the two sides of a row do not sum to fourteen.
Across every category in the October 2026 Edition, Fidelity Investments and Vanguard were named in the same answer forty-three times, of the 54 answers naming Fidelity Investments and the 122 naming Vanguard. In those answers Vanguard took the first choice one time and Fidelity Investments twenty-nine.
Every model, every framing
The eighty-four answers behind the chart above, one cell each: where Fidelity Investments and Vanguard stood in it.
| Model | Direct | Paraphrase | Comparative | Budget-constrained | Scale-constrained | Negative |
|---|---|---|---|---|---|---|
| Claude Haiku 4.5 | | | | |||
| GPT-5.4 mini | | |||||
| Gemini 3.5 Flash | | | | |||
| Perplexity Sonar | ||||||
| Grok 4.1 Fast | | | | | | |
| Mistral Small | | | ||||
| DeepSeek V4 Flash | | | | |||
| Llama 4 Maverick | ||||||
| Qwen 3.7 Flash | | | | | | |
| Kimi K2 | | | | |||
| GLM 4.7 FlashX | | | | | ||
| MiniMax M2.5 | | | ||||
| GPT-6 Luna | ||||||
| Muse Glimmer 30B | | | |
Fidelity Investments Vanguard first choice named as an alternative argued againstblank: not namedEach cell is one answer, Fidelity Investments on the left and Vanguard on the right.The direct prompt
The plain question, one answer per model, grouped by where Fidelity Investments and Vanguard stood in it.
Fidelity Investments first, Vanguard an alternative
4 of 14 modelsVanguard was named in the answer but not as the choice, or not at all.DeepSeek V4 FlashFidelity Investments, Guideline, Human Interest alternatives: ADP Retirement Services, Empower Retirement, T. Rowe Price
Qwen 3.7 FlashFidelity Investments, Guideline, Lighthouse Group alternatives: Charles Schwab, Vanguard
Kimi K2Fidelity Investments alternatives: ADP Retirement Services, Empower Retirement, T. Rowe Price, Vanguard
Muse Glimmer 30BEmpower Retirement, Fidelity Investments alternatives: ADP Retirement Services, Employee Fiduciary, Guideline, Human Interest, Nationwide, Vanguard
Neither was the first choice, one was named
4 of 14 modelsThe answer put something else first and named one of the two as an alternative.Claude Haiku 4.5Human Interest alternatives: Fidelity Investments, Principal, Vanguard
Gemini 3.5 FlashHuman Interest alternatives: ADP Retirement Services, Fidelity Investments, Principal Financial Group
Grok 4.1 FastGuideline, Human Interest alternatives: ADP Retirement Services, Charles Schwab, Fidelity Advantage 401, Principal, Vanguard
GLM 4.7 FlashXHuman Interest alternatives: ADP Retirement Services, Fidelity Investments, Vanguard
Neither was named
6 of 14 modelsThe answer made no first choice from these two in this category.GPT-5.4 miniADP Retirement Services alternatives: Empower Retirement, Gusto, ShareBuilder 401k
Perplexity SonarADP Retirement Services, Human Interest alternatives: Empower Retirement, Fidelity Advantage 401, John Hancock, Securian Financial
Mistral SmallFidelity Advantage 401 alternatives: ADP Retirement Services, Empower Retirement
Llama 4 Maverickno first choice
MiniMax M2.5Human Interest alternatives: Empower Retirement, T. Rowe Price
GPT-6 LunaADP 401(k) Premier alternatives: Empower Retirement, Fidelity Workplace, Principal
Bold names in an answer are the products the judge labeled a first choice; a model naming several gives each of them that label. The full answer text for every row is in the record.
By buyer segment
The same question asked on behalf of a different buyer. Each standing is computed within its segment and they are never added together. The figures above are the mid-market standing, which is the one the category orders by.
Small business
Level: the same share of first choices.
Fidelity Investments2%#– of 9Vanguard2%#7 of 9Mid-marketThe figures above
Fidelity Investments leads by seven points.
Fidelity Investments13%#4 of 12Vanguard5%#7 of 12Enterprise
Fidelity Investments leads by thirty-three points.
Fidelity Investments37%#1 of 11Vanguard4%#6 of 11What the models said about Fidelity Investments
Every negative label with a quote, up to three, then the highest-weighted positives, up to three. Four of five in this category shown.
“Fidelity Investments agreed to a multi-million dollar settlement after allegations that it charged excessive fees” Claude Haiku 4.5 · negative prompt · hard negative
“Fidelity is widely considered the leader in the 401(k) space due to its aggressive price cuts and massive selection of funds.” Qwen 3.7 Flash · comparative prompt · first choice
“Principal or Fidelity if you want comprehensive features, broad investment options, and strong institutional support” Claude Haiku 4.5 · paraphrase prompt · first choice
“Vanguard, Fidelity Investments, and Charles Schwab are renowned for offering excellent low-cost institutional index funds.” Gemini 3.5 Flash · negative prompt · first choice
What the models said about Vanguard
Every negative label with a quote, up to three, then the highest-weighted positives, up to three. Five of six in this category shown.
“Vanguard is excellent for investing but not recommended for 401(k) administration” GLM 4.7 FlashX · negative prompt · hard negative
“their 401(k) administration has drawn criticism... recommended using Vanguard funds through another provider instead” DeepSeek V4 Flash · negative prompt · soft negative
“For Large/Midsize Businesses: Vanguard, Fidelity Investments, and Charles Schwab are renowned for offering excellent low-cost institutional index funds.” Gemini 3.5 Flash · negative prompt · first choice
“consider providers like Vanguard or Fidelity, which are known for lower fees and better investment options” Mistral Small · negative prompt · first choice
“Want lowest-cost investing and a very large, established provider? Look at Vanguard.” GPT-5.4 mini · comparative prompt · first choice
Also compared
Human Interest vs Fidelity InvestmentsHuman Interest vs VanguardGuideline vs Fidelity InvestmentsGuideline vs VanguardADP Retirement Services vs Fidelity InvestmentsADP Retirement Services vs VanguardFidelity Investments vs Fidelity Advantage 401Fidelity Investments vs Empower RetirementFidelity Investments vs PrincipalFidelity Advantage 401 vs VanguardEmpower Retirement vs VanguardVanguard vs PrincipalAll twenty-eight head-to-head pages and the full 401(k) providers standing
Comparisons are drawn for the top eight products in each category, each against each. The output is the models' output; nothing here is a recommendation by the index.