Northern Funds files to convert five mutual funds, and three would change indexes

Northern Funds has filed to turn five mutual funds into exchange-traded funds, and three of them would leave the indexes they track now.

The filing is a Form N-14, the registration a fund uses before it can issue shares in a reorganization. It reached the Securities and Exchange Commission on Friday, October 2, 2026, and it is not effective. The cover says the information may be changed, and the new shares may not be sold until it is.

Three indexes would change

The registration says the new ETFs would be managed in a substantially similar way, except that three would track a new index.

Stock Index Fund, ticker NOSIX, tracks the S&P 500. The registration describes that index as 503 large U.S. stocks, worth about $5.52 billion to $5.13 trillion as of Friday, May 29, 2026.

The new series would track the MSCI US 500 Index, the largest 500 U.S. issuers ranked by each company's full market value. As of Friday, July 31, 2026, the filing says that index held 507 stocks, worth about $1.23 billion to $4.63 trillion.

Mid Cap Index Fund, NOMIX, would leave the S&P MidCap 400 for the MSCI US 400 Index, the 400 issuers ranked 501 through 900. On the May date, the S&P index's largest company was worth about $55.4 billion. On the July date, the MSCI index's largest was about $28.66 billion.

Small Cap Index Fund, NSIDX, would leave the Russell 2000, about 2,000 of the smallest stocks in the Russell 3000, for the MSCI US 2000 Index, issuers ranked 1,001 through 3,000. That index held 1,981 stocks on the July date, the filing says, the smallest worth about $7.7 million.

The international fund already tracks the MSCI EAFE Index, and the new series keeps that index.

The Tax-Advantaged Ultra-Short Fixed Income Fund is not an index fund. It seeks the best after-tax return it can earn from taxable and tax-exempt short-term bonds, for someone in the top federal tax bracket, while trying to preserve principal. It expects an average maturity of six to eighteen months and plans to hold investment-grade debt, at least half of it in municipal bonds.

Those closings are proposed for on or about those two Fridays. The four equity ETFs would list on NYSE Arca. The ultra-short ETF would list on Nasdaq.

Each mutual fund would hand its investments and its debts to the matching ETF, holders would receive ETF shares of the same value, and the mutual fund would then close. Northern Trust Investments, which already runs the mutual funds, would keep running the ETFs.

The new fees are not set. The registration lists the mutual funds' net expenses at 0.05% for Stock Index, 0.10% for each of the other three stock funds, and 0.25% for the ultra-short fund. A supplement filed Friday, September 25, 2026 says each new ETF's single fee will be equal to or lower than those figures.

The same registration proposes a management fee that is not yet final: 0.04% for the MSCI US 500 ETF, 0.09% for each of the other three stock ETFs, and 0.23% for the ultra-short ETF. That fee is meant to cover ordinary operating costs, and the filing says total expenses should be lower than the mutual funds' net expenses.

On Monday, September 28, 2026, Northern Trust put the five funds at $32.7 billion as of June 30, 2026, including $19.3 billion in Stock Index. The filing's own provisional figures differ slightly, and come to $33 billion as of the same date, with Stock Index at $19.4 billion. Income Equity, at $316 million, is a sixth fund on a separate registration filed Friday, September 25, 2026, not this one.

The registration does not assign tickers. Northern Trust named planned symbols that day: NTLC for the stock fund, NTMC for mid cap, NTSC for small cap, NEFA for international and TAXU for the ultra-short fund.

The firm reported $27 billion in ETFs as of June 30, 2026. On those figures, completing the five-fund conversion would more than double that business.

Northern Trust has called the six-fund plan the largest mutual-fund-to-ETF conversion in the industry's history. Dimensional Fund Advisors converted four equity funds with $28.8 billion in 2021, and JPMorgan Asset Management announced further conversion plans in 2025.

What a shareholder has to do

The registration says no shareholder vote is required. The board, including the trustees who are independent of the adviser, approved the plan on Thursday, September 24, 2026, and found that it would not dilute existing shareholders. Holders should receive an information statement in the fourth quarter of 2026.

To receive ETF shares, a holder has to keep the mutual fund in a brokerage account or retirement plan that can hold an ETF. The supplement says to make that move at least a month before the closing, or the shares may be sold for cash. Cash paid to someone who cannot hold the ETF can be taxable, and so can cash paid instead of a fraction of an ETF share.

The exchange of whole shares is intended to be tax-free, as a change in the fund's form. A warning that is not yet final says cash redemptions of holders who cannot take ETF shares could create capital gains inside the fund, and holders who stay might owe more tax than they would have without the conversion.

For the three February funds, the last day to buy is Wednesday, February 24, 2027, and the last day to redeem or exchange is Thursday, February 25. The two March funds follow the same pattern, on Wednesday, March 3, 2027, and Thursday, March 4.

The supplement says the registration may be amended or withdrawn. The reorganization agreement allows the plan to be called off if a closing has not happened by Thursday, September 30, 2027, unless the parties extend that date.

The firm said the conversions are meant to give holders more tax efficiency, the chance to trade through the day, and a clearer view of holdings. Mutual fund shares are priced once a day. ETF shares trade on an exchange while the market is open.

"Northern Trust Asset Management plans to bring established strategies into a structure that better reflects how many clients are implementing portfolios today," Dave Abner, global head of ETFs and funds at Northern Trust Asset Management, said on Monday, September 28, 2026.

Until a closing, Stock Index Fund still tracks the S&P 500, not the largest 500 U.S. issuers.