If recent economic developments are any guide, there’s an argument for saying that we could be at the cusp of a new bull market for stocks.

For this reason, I’ve been holding tight to a couple of investment trusts in my portfolio. There’s also one I’m tempted to buy when I can find the cash.

Scottish Mortgage Investment Trust

The once-incredibly-popular Scottish Mortgage Investment Trust (LSE: SMT) has had a tricky couple of years. Go back to November 2021 and the share price stood above 1,500p. Fast-forward to today and the very same stock changes hands for a little over 821p. This shows just how averse investors have been to many go-go growth stocks in recent times.

On a more optimistic note, I reckon these are ideal conditions for patient Fools to consider loading up. And that’s exactly what I’ve been doing. Scottish Mortgage is the second-largest holding in my Stocks and Shares ISA.

An unwelcome rebound in inflation could stifle any positive sentiment. However, I’m encouraged by last week’s decision by the US Federal Reserve to (finally) begin lowering interest rates, especially as the trust has stakes in private companies that might IPO under the right conditions. Elon Musk’s SpaceX is surely one candidate.

Whisper it, but Scottish Mortgage could be about to make up for lost time.

Smithson Investment Trust

Another investment trust that I own is FTSE 250 constituent Smithson (LSE: SSON). Rather than buy glitzy tech titans, manager Simon Barnard goes fishing for stocks further down the market food chain.

Again, this strategy has struggled in a high interest rate environment since many/most smaller businesses take on debt to grow. But with the prospect of repayments coming down, they could be poised to outperform.

With a relatively concentrated portfolio of just 34 holdings, there’s still a fair dollop of risk here. Management fees will impact on returns too.

On the other hand, I’m comforted by the fact that Smithson picks stocks using the same modus operandi as its big brother — Terry Smith’s multi-billion pound Fundsmith Equity Fund. He looks to buy quality companies (that are able to reinvest cash flow at high rates of return) and then ‘do nothing’.

Smithson has been out of favour for a while but I suspect things could be about to get interesting.

Blackrock World Mining Trust

A final FTSE member that I think could do very well (and I’m considering buying) is Blackrock World Mining Trust (LSE: BRWM).

Sadly — but unsurprisingly — this hasn’t been the case recently. The shares are down nearly 11% in the last 12 months as economic woes have constrained demand from big metal buyers like China. This helps to underline the point that investing in anything commodity-related is not for the faint-hearted.

Then again, this trust spreads investors’ money around all of the biggest explorers/producers in the sector, including FTSE 100-listed beasts like Rio Tinto, Anglo American and Glencore.

This diversification won’t stop it from falling in value. After all, none of these businesses have a say on where metal prices go next. But it does feel a whole lot less scary than going ‘all-in’ on just one player.

The chunky dividend yield should help to offset any temporary weakness in the share price too.