DODIX, FTBFX, BOND are managed bond funds while AGG,BND and VBTLX follow the US Total bond index and why they are very close long term.

Of course, the objective of an index fund is to track its target benchmark closely. On this score, three of our four funds came up significantly short. The Total Bond Market Index Fund--our oldest and biggest bond index fund--returned 8.3%, well below the 10.3% return of the Lehman Aggregate Bond Index. Our Short-Term and Intermediate-Term Bond Index Funds also trailed their target indexes by about 2 percentage points. The Long-Term Bond Index Fund's return was within 0.4 percentage point of the target.
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As we explained in our report to you six months ago, our funds' returns will typically differ from those of the indexes for two primary reasons: The funds incur expenses that the indexes do not, and the funds' holdings do not exactly replicate those held by the indexes. The expense difference will always work against us in our goal of providing close tracking. The difference in holdings arises from our "sampling" approach to indexing, which is necessary because it would be impractical and very costly to own all the bonds in the target indexes.

Those are huge discrepancies in the bond world, and an embarrassment for the Malvern, Pa., firm whose name is practically synonymous with index funds. The flexibility to deviate from the benchmark index is disclosed in the Vanguard's prospectuses for its bond index funds, but nonetheless is surprising for those under the impression an index fund mechanically invests in the securities making up its benchmark.

In addition, each Fund keeps industry sector and subsector exposure within tight boundaries relative to its target index. Because the Funds do not hold all the securities in their target indexes, some of the securities (and issuers) that are held will likely be overweighted (or underweighted) compared with the target indexes. The maximum overweight (or underweight) is constrained at the issuer level with the goal of producing well-diversified credit exposure in the portfolio.

since the first week of March

... these results mostly reflect how exorbitant valuations were at the start of that 20-year span, and not how depressed they are today.
...the S&P 500 isn’t yet statistically cheap, but it is vastly more attractive than it was just five weeks ago.
... not a single equity sector generated a double-digit annualized return over the last 20 years, nor did any major asset class.
Incredibly, the S&P 500 Energy sector (+2.4%) and Technology sector (+2.7%) delivered about the same results to those who bought them in March 2000 and held on for the ride.
In sum, initial valuations matter, and the only good thing to come out of the last five weeks’ action is that the “cost of entry” into the S&P 500 has finally closed in on its historical average, and almost all other stock market cohorts (domestic and international) are well below their averages. Veteran investors will recall that the Y2K peak proved to be an excellent time to shift into Mid and Small Caps, and it’s worth noting that median valuations for these stocks are 15-25% below those prevailing at that historic turning point. Keep this good news in mind when dealing with the coming onslaught of bad news.

The following provides a brief recap of the RiverNorth conference call held on March 19th.
Capital markets and economic volatility/uncertainty has led to unprecedented volatility in the CEF markets
RiverNorth estimates that 90%+ of the CEF market is owned by retail – and they are in full retreat
Co-portfolio manager Steve O’Neill described some of the CEF price action last week as a “9.5 out of 10 on the CEF panic scale”
Discounts hit (and in some cases exceeded) levels last seen during the Global Financial Crisis of 2008
To keep investors appraised of the opportunity set, RiverNorth started posting discount data here: rivernorth.com/cef-discount-info
The opportunity is broad based – nearly all CEF asset classes trading at historically wide discounts

Core tenets such as what constitutes a safe asset, the value of bonds as a portfolio hedge, and expectations for returns over the next decade are all being reconsidered as governments and central banks strive to avert a global depression.
QE Kills Valuation Models -- Ordinarily, the prospect of a multi-trillion-dollar government spending surge globally ought to send borrowing costs soaring. But central bank purchases are now reshaping rates markets -- emulating the Bank of Japan’s yield-curve control policy starting in 2016 -- and quashing these latest volatility spikes.
Inflation Risk -- Many market veterans agree that faster inflation may return in a recovery awash with stimulus that central banks and governments may find tough to withdraw...“There’s tension in all of this,” said Hamish Pepper, fixed-income and currency strategist at Harbour Asset Management Ltd. in Wellington, New Zealand. “I don’t think it’s necessarily about waking up one morning realizing that bond yields should be 100 basis points higher from here -- but you have to think about inflation at some point.”
Haven or Not? -- “Will government bonds play the same role in your portfolio going forward as they have in the past?” he said. “To me the answer is no they don’t -- I’d rather own cash.”
“It’s very hard to look at this in a historical context and then apply an investment framework around it,” said BlackRock’s Thiel. “The most applicable period is right before America entered WW2, when you had gigantic stimulus to spur the war effort. I mean, Ford made bombers in WW2 and now they’re making ventilators in 2020.”