At a glance
GRN charges 0.75% a year, above the 0.66% average of the 7 funds most like it (the 4th cheapest of 7). It has $20.5M in assets, the 8th largest of that group. Over the past year it returned +14.4% with distributions reinvested (S&P 500: +11.5%), 7th of those 8 funds; over three years it returned +3.9% a year. At its worst it fell 40.5% in the 2020 crash (S&P 500: 33.7%) and 40.6% in the 2022 bear market (S&P 500: 24.5%), and was back at its earlier high 3 months and 5 months after the lows.
The short version
iPath Series B Carbon Exchange-Traded Notes (GRN) is an exchange-traded note, not a fund: unsecured Barclays debt that pays a carbon-linked index's return, minus a 0.75% yearly fee. Its narrow carbon focus, unlike the broad commodity and gold funds it is grouped with, is the main reason someone might own it. It pays no income, carries Barclays' credit risk and, at about $20.5 million in assets, is the smallest of eight in its group.
Price history
The interactive chart needs JavaScript.
GRN +14.4% over the year to Oct 27, 2026, total return with distributions reinvested.
How it has behaved
| YTD | 1 yr | 3 yr | 5 yr | 10 yr | Since start | |
|---|---|---|---|---|---|---|
| GRN price data to Oct 27, 2026 | +3.5% | +14.4% | +3.9% | +8.6% | — | +18.3% |
- Over the year to Oct 27, 2026, GRN returned +14.4%, 7th of 8 among similar funds.
- Its 5-year annualized return was +8.6%.
- In the 2020 COVID crash it fell 40.5% and regained its old high 3.4 months after the low.
- Its worst full calendar year was 2024 (-7.3%); its best was 2021 (+147.2%).
- The deepest fall in its price history was 48% (Feb 27, 2023 to Feb 22, 2024), not yet recovered.
Show as a table
| Year | Price data |
|---|---|
| 2026 (to date) | +3.5% |
| 2025 | +20.3% |
| 2024 | -7.3% |
| 2023 | -3.0% |
| 2022 | -0.1% |
| 2021 | +147.2% |
| 2020 | +30.5% |
| 2008 financial crisis stocks fell Oct 9, 2007 – Mar 9, 2009 | Before this security existed |
|---|---|
| 2020 COVID crash stocks fell Feb 19, 2020 – Mar 23, 2020 | Lost 39.2% over that stretch · deepest drop along the way 40.5%, back to its old high 3.4 months after the low |
| 2022 bear market stocks fell Jan 3, 2022 – Oct 12, 2022 | Lost 20.7% over that stretch · deepest drop along the way 40.6%, back to its old high 5.4 months after the low |
How it works
GRN doesn't choose holdings, because it holds nothing on investors' behalf. It is an exchange-traded note (ETN): an IOU from Barclays Capital that promises to pay the return of a carbon-linked index, minus fees. There is no portfolio manager, no basket of assets and no holdings report. Unlike an ETF, it has no fund prospectus either. The index's contents, weighting and rebalancing rules are set out in Barclays' offering documents for the notes, which are worth reading before owning them.
Two mechanics matter most. First, the 0.75% yearly fee is taken out of the index return, so the note will trail its index over time. Second, every payment depends on Barclays. Because the notes are unsecured, meaning no collateral backs them, holders are simply creditors of the bank: if it could not pay, they could lose money even if the index rose. Barclays can also redeem the notes early, ending a holding on the bank's timetable rather than the investor's.
GRN is neither leveraged (amplifying the index's moves) nor inverse (betting against it). It has made no distributions, so all gains and losses show up in its price. Like other ETNs, it trades on an exchange, and its market price can drift from the value the index return implies.
What it really costs
- GRN charges 0.75% a year, versus an average of 0.66% for the similar funds below (4th of 7, cheapest first).
Structure and tax notes
- An exchange-traded note: unsecured debt of the issuing bank, not a fund. It owns no assets on investors’ behalf; it pays the index return minus fees only as long as the issuer can pay, so the bank’s credit matters, and the issuer can redeem the notes early.
In a retirement portfolio
Its narrow carbon focus, large price swings, lack of income and reliance on Barclays' credit make it a higher-risk add-on rather than a foundation.
As a small position, GRN could add carbon exposure that most stock and bond funds lack, but it has been a rough ride. It launched in September 2019, so it has no 2008 record. It fell 40.5% in the 2020 COVID crash, recovering by June 29, 2020, and 40.6% between February 4 and March 7, 2022, recovering by August 17. Its deepest drop, 48% from February 2023 to February 2024, had not been recovered as of October 27, 2026. Its weakest calendar year, 2024, lost just 7.3%, so year-end figures hide much of the swing. Anyone forced to cash out mid-slide could lock in a steep loss.
GRN pays no income, so withdrawals would mean cashing out shares. Its 0.75% fee tops the 0.66% average for its comparison group. Past results don't predict future ones, and a plan should weigh the whole portfolio, not one holding.
Who it may suit — and who should look elsewhere
May suit
- Investors who want a targeted carbon position as a small add-on, rather than the broad commodity baskets most funds in its group track.
- Holders who accept Barclays' credit risk and the chance the bank redeems the notes early, ending the position on its schedule.
- People who can tolerate swings like the 40%-plus drops in 2020 and 2022 and a 48% fall still unrecovered as of October 27, 2026.
Look elsewhere if
- Retirees who need regular income: GRN has made no distributions, so any cash must come from cashing out shares.
- Investors who want a fund that owns assets for them, not an unsecured Barclays note whose payout depends on the bank's ability to pay.
- Investors after broad commodity exposure: funds like BCI, at 0.26%, cost less, and GRN's three-year return ranked last of eight as of October 27, 2026.
Close alternatives
Matched by legacy category (no holdings report for this fund).
| Fund | Cost | Net assets | 1 yr | 3 yr |
|---|---|---|---|---|
| GRN this fund | 0.75% | $20.5M | +14.4% | +3.9% |
| PHYS Sprott Physical Gold Trust | — | $10.70B | +2.4% | +25.4% |
| PDBC Invesco Optimum Yield Diversified Commodity… | 0.59% | $4.90B | +53.4% | +14.8% |
| FTGC First Trust Global Tactical Commodity Strat… | 1.02% | $2.50B | +37.4% | +16.9% |
| BCI abrdn Bloomberg All Commodity Strategy K-1 … | 0.26% | $1.40B | +37.6% | +14.9% |
| DBC Invesco DB Commodity Index Tracking Fund | 0.85% | $1.30B | +52.2% | +15.3% |
| GSG iShares S&P GSCI Commodity-Indexed Trust | 0.75% | $1.10B | +59.6% | +18.7% |
| COMT iShares U.S. ETF Trust iShares GSCI Commodi… | 0.48% | $683.2M | +54.4% | +17.0% |
Questions investors ask
Is GRN an ETF or an ETN?
GRN is an ETN, not an ETF. An exchange-traded note is unsecured debt issued by a bank, here Barclays Capital. It owns no assets on investors' behalf; it simply promises to pay the return of a carbon-linked index, minus fees. That means holders depend on Barclays' ability to pay, and Barclays can redeem the notes early. An ETF, by contrast, holds a portfolio of assets kept separate from its sponsor.
Does GRN pay dividends?
No. GRN has made no distributions, so it provides no income. Any return comes only from changes in the note's market price, which follows a carbon-linked index's return minus a 0.75% yearly fee. Investors who need cash from it would have to cash out shares, which could mean doing so after a steep fall, such as the 48% decline from February 2023 to February 2024.
What is GRN's expense ratio?
GRN's expense ratio is 0.75% a year, deducted from the index return rather than billed separately. That is above the 0.66% average of the commodity funds it is compared with, and it ranks fourth of seven on cost. Among those funds, BCI charges 0.26% and PDBC 0.59%, while GSG matches GRN at 0.75% and FTGC charges 1.02%. Those funds follow broad commodity strategies, not carbon, so the comparison is about cost, not strategy.
What's the difference between GRN and GSG?
GSG, the iShares S&P GSCI Commodity-Indexed Trust, follows a broad commodity index, while GRN is a Barclays note tied to carbon, so they aren't like-for-like substitutes. Both charge 0.75% a year, but GRN is unsecured bank debt that owns no assets. As of October 27, 2026, GSG returned 59.6% over one year and 18.7% a year over three, versus 14.4% and 3.9% for GRN. GSG is also far larger, with about $1.1 billion in assets versus $20.5 million.
How volatile is GRN?
GRN has been highly volatile. As of October 27, 2026, its volatility, a measure of how widely returns swing, was 31.4% over three years and 28.9% over one year. It fell about 40% in both early 2020 and early 2022, recovering within months each time, but its 48% drop from February 2023 to February 2024 had not been recovered by that date. Calendar years ranged from a 147.2% gain in 2021 to a 7.3% loss in 2024.